Introduction

One task of the Ministries of Finance in many countries is to produce revenue estimates with regard to corporation tax. Such estimates have to a large extent, when it comes to corporations, been restricted to theoretical evaluation of the behavioural effects induced by changes in the tax code. The lack of micro data has typically made it difficult to conduct a valid empirical investigation. Estimation of behavioural factors, therefore, plays an important role in assessing the financial implications of proposals for changes in the tax code. It is desirable that more qualified assessments are enabled. A change in this direction will imply a better revenue estimate with regard to corporation tax. Another main task of the typical Ministry of Finance is revenue forecasting. Corporation tax is an area where forecasts have been unreliable. The forecasting failure blurs the assumed connection between the development of the economy and income tax. The aggregate material used has not enabled the necessary provisions in the forecasts for corporations’ allocation of profits over time. It may be assumed that such provisions are utilized to a varying degree depending on the individual firm’s economic situation (see, for example, Forsling, 1998). To capture the individual firm’s economic behaviour, it is necessary to use micro data. The estimation of behavioural factors is thus an important part of improving the methods for forecasting corporation tax revenue. Ministries of Finance are to a large extent dependent upon the development of a micro simulation model for this purpose.

As Shaym-Sunder and Myers (1999) rightly mentioned, corporate financing decisions reflect many motives, forces and constraints, and they called for more elaborate theoretical and empirical models that can deal with these issues. Shahnazarian (2005) shows, using a theoretical model, that combining an upper constraint on dividends, a lower constraint on dividends due to shareholder preferences, an interest rate that increases with the debt ratio, a “tax incentive” for firms to substitute debt for retained earnings, and retained earnings for new share issues (which is the case in most OECD countries) leads to a pecking-order financial structure: a typical firm will start to finance a new investment by issuing new shares in combination with debt, then grow by financing its investments with retained earnings and borrowing, and eventually stop growing and distribute all profits. The study also shows that repurchases of shares will speed up this growth path and that economic depreciation may make the firm want to stop the decline in its capital stock earlier. Findings in these studies indicate that estimation of behavioural factors is an important part of improving the methods for evaluating and forecasting the business performance. However, the evaluations of tax revenue effects induced by changes in the tax code within Ministries of Finance in many countries often exclude these behavioural effects.

The simulation model introduced in this paper is aimed to help practical policy making, by providing a tool for analyzing the behavioural effects induced by changes in the tax code and for forecasting tax revenues. Furthermore, the model is also aimed at improving the business practice for analyzing business performance.

The idea behind the dynamic micro econometric simulation model presented can be summarized in the following way. In the simulation module, we define the stock and flow variables of firms and specify the evolution of the stock variables over time in terms of difference equations, using the information in the firm’s three basic financial statements: the balance sheet, the income statement, and the statement of changes in financial conditions. This so-called system dynamic approach has more frequently been used in natural and technical sciences. It has also been used in the business field. An original reference is Forrester’s (1961) industrial dynamic system. The idea behind system dynamic modelling of corporate firms has also been called financial statement modelling. A very simple example of such modelling is given in Benninga (1989). Kumar and Vrat (1989) and Clarke and Tobias (1995) provide a review of system dynamic modelling with regard to a corporation. This way of modelling has, to our knowledge, not been used extensively in the field of economics. This could be due to the fact that the implementation of the idea into a functioning model is not an easy task. There is of course one exception. Tongeren (1995) uses this approach in micro simulation modelling of Dutch firms. This is achieved by focusing on the relationship between the firms and the economy as a whole. However, Tongeren’s simulation model explores micro-macroeconomic relationships. This is not the case in the model presented in this paper. The behaviour of firms is instead decided by using econometric tools. In our model, we use macro economic variables as explanatory variables in our estimations of the behaviour of the firms. As a result, we do not see the repercussions from the behaviour of the firms on the macroeconomic variables.

There is, however, an extensive literature in the field of dynamic optimization that indirectly uses a system dynamic approach. In the field of corporate taxation and finance there are many examples of this indirect use of a system approach. Sinn (1987), Kanniainen and Södersten (1995) and Shahnazarian (1996, 2005) are examples of such studies. Shahnazarian (1997) uses such an approach in his theoretical and numerical evaluation of the Swedish tax reform act of 1994. In this paper the emphasis is on the way in which the complex structure of a firm’s dynamics is specified, though the micro foundations of such dynamics are analogous to the existing academic literature on investment behaviour of firms under taxation. More generally, the models used in these papers are often a simplified version of basic system dynamic models, since in this field the authors are usually interested in examining the impact of taxation on corporate financial policy and the cost of capital.

The focus in this paper, on the other hand, is on the use of econometric tools rather than theoretical ones. In the statistical module (behaviour modelling), the behaviour of the firms is modelled and estimated in two steps. We use a dynamic optimization model to derive the relationships between different decision variables. These relationships are derived by subjecting the optimization to investigations of a comparative static sort. The relationships between different decisions variables are then estimated using robust estimation methods depending on the nature of the variable. The major gain in building and employing micro simulation models is that such models utilize information derived from existing microdata. The use of microdata enables the economic behaviour of individual firms to be captured. However, analysis of microdata often reveals that influential observations are present. This is especially the case for micro data on firms. The data in hand include both large corporations and small enterprises. Therefore, it is not advisable to exclude the information on these firms just because they happen to be big or small corporations. The estimation method that is used to estimate firms’ behaviour regarding different decision variables must be able to deal with this fact. This is especially important for models that are aimed to be used for practical purposes. When influential observations are present and have an unacceptable effect on derived least squares estimate, the best remedy is to apply a robust estimator rather than deleting these observations.

In our estimations, we use pooled data derived from accounting and taxation information from 19971999 resulting in a three-year panel. In this paper, we use the data for stock companies from the database named FRIDA (which stands for Firm Register and Individual Databases). FRIDA was developed in 1997 by the Swedish Ministry of Finance and Statistics Sweden. FRIDA is composed of several databases for firms with different organization forms. This includes databases for joint stock companies (which also includes close companies), cooperatives, partnerships, associations, foundations, and proprietorship (or sole trader).

The purpose of this paper is to provide an overview of the model we have developed without going too far into technical details, highlighting one or two key areas of innovation, and presenting some illustrative results/applications. The aim is therefore to show how the simulation model can be used to simulate firms’ three basic financial statements and to evaluate the impact of changes in tax laws. This is the reason why we refrain from presenting the dynamic optimization problem, the estimation methods and the results and refer the reader to Shahnazarian (2004) for the details. However we introduce the framework of the simulation model within a simple model with two assets in Appendix 2. We strongly recommend the reader to read this appendix before continuing with subsequent sections. In Section 1, we give a brief overview of the corporate tax system in the period covered in the analysis. In Section 2, we describe the structure of the different modules in the simulation model. However, we provide a formal description of the simulation model in Appendix 3. To make this paper easier to read, we also include an index with an explanation of the symbols used in Appendix 1. In Section 3, we describe the data used in both the statistical and the simulation modules. In Section 4, we present the simulation results using the current tax rules. Section 5 provides an evaluation of the simulation model by examining the forecasting accuracy of the simulation results. In Section 6, we analyze the simulation results for a hypothetical corporate tax rate reduction of three present. In Section 7, we present the simulation results for a hypothetical change in the macro economic development. The discussion that follows sums up and concludes the paper.

1. The taxation of incorporated businesses in Sweden

Prior to 1991, Swedish company taxation was characterized by high statutory tax rates combined with liberal reserve facilities. The government used the company taxation, as part of the general economic policy, to direct firms’ behaviour. The gap between the statutory tax rate and the effective tax burden on a company’s profits became very large because of the generous reserve facilities. The belief that the tax burden was different for different companies was one of the reasons why a reform was believed to be necessary. The direction of the 1991 reform and reforms thereafter were to broaden the tax bases, cut the tax rates and simplify the tax rules. The corporate income tax rate was lowered to 28 per cent, while the tax base was broadened. The reason for choosing this particular tax rate was to achieve uniformity between the taxation of the corporation’s income and the taxation of capital income.

In Sweden the tax balance sheet of the firm must coincide with the commercial balance sheet (so-called uniform reporting). The main connection between the accounting profit and the taxable profit is that the calculation of taxable income must be undertaken according to good accounting practice, which is based on accounting laws (except where the tax rules specifically differ from the accounting rules). Most of the balance-sheet allocations prior to 1991 were removed. An exception was the new reserve option periodical reserve fund. Enterprises are allowed to allocate, tax-free, a maximum of 25 per cent of their annual profits to a periodical reserve fund. A firm which has made an allocation to a periodic reserve fund can make a deduction from its taxable income. The deduction is limited to a maximum of 25 per cent of the current year’s profit. The reserve must be returned to taxable status no later than the fifth year of allocation. The reason for introducing this option was to bring about an effective average tax rate lower than 28 per cent. Among the remaining balance-sheet allocations it is important to mention accelerated depreciation of machinery and equipment. The depreciation rate, for tax purposes, for machinery and equipment is 30 per cent if the declining-balance method is used, while it is only 20 per cent if the straight-line method is used. For buildings the straight-line method applies and, depending on type of asset, the depreciation rate is 1.5–5 per cent.

2. The different modules in the simulation model

The basic idea behind the simulation model is to combine the dynamic behaviour of the corporate system with a statistical model that captures the development and the interrelationships between the firms’ different decision variables. The dynamic behaviour of the corporate system is captured in the simulation module by several difference equations that identify how different variables in the firms’ balance sheets change over time using the information in the firms’ three basic financial statements: the balance sheet, the income statement, and the statement of changes in financial conditions. The firms’ decisions regarding the flow variables are modelled in a statistical module. We use the dynamic optimization problem to derive the relationships between these variables. These relationships are then estimated using different robust estimation methods. The estimated functions from the statistical module are then inserted into the difference equation system. The difference equation system together with the estimated relationships is finally solved numerically in a recursive manner to be able to simulate new financial statements.

The simulation module maintains three interrelated sets of accounts: a balance sheet account, a profit-loss account, and the statement of changes in financial conditions. Altogether, these three accounts provide a financial description of the firms at a given moment in time. The first is the income statement. A second document is a statement of sources and uses of funds (the cash flow statement). These two statements are flow statements, showing various financial flows occurring during the course of one year. The third statement is the balance sheet, which is a stock concept. It shows the value of various company assets and liabilities outstanding at the end of each financial year. Appendix 3 gives a technical description of the simulation model.

The structure of the statistical module can be summarized as follows. The approach we use to identify the recursion follows the traditional approach in economic theory. We use the solution (total differentiation of the first order condition) of a dynamic optimization model to find out the economic relationships between the changes in different balance sheet items (see Appendix 1). However, the derived relationships only include firm-specific variables such as income-statement variables, balance-sheet variables, and variables that capture the legal and accounting constraints. But, we know that firms operations are highly dependent on the firms’ expectations regarding the business cycle and the development of the market. Therefore we also include other regressors in our estimations of corporate decision variables to control for these factors. The market conditions are captured by the following three variables: a variable that identifies the market in which firms may have their business, a variable that captures the market share of these firms, and a variable that captures the location of the firms. Moreover, we use two different variables as proxies for the maturity of firms. The firms’ expectations regarding the business cycle are captured by including one of the two following macroeconomic variables: the change in GDP and the real interest rate on a government bond with a maturity of 10 years. To be able to include the macro economic variables and variables that capture the development of the market in our estimations, it proved necessary to pool data from 1997–1999.

The recursive method used in the statistical module is as follows. First, we estimate the economic depreciation of machinery and equipment, the sale of machinery and equipment, and the investments in these assets. Second, we estimate the economic depreciation of buildings, the net investments in these assets, the net change in other fixed assets and the net change in current assets. Third, having established the net changes in different assets, we go on to investigate the funds available to undertake such investments. This is done in the following order. We estimate the net change in long-term liabilities, the net change in current liabilities, the net change in share capital, and the net change in restricted reserves. Finally, we estimate operating income before depreciation, financial income, financial expenditure, tax allowances for depreciation, reversals from periodical reserves, allocations to periodical reserves, changes in other untaxed reserves, net group contributions, other allocations, tax liabilities, other tax adjustments, the tax depreciation of buildings, and reductions in taxes.

We use robust estimation methods to estimate these variables. The use of robust estimation methods is one of the main innovations we wish to emphasize. The reason for using robust estimation methods is the fact that microdata on firms often reveal that influential observations are present. The estimation method that is used to estimate firms’ behaviour regarding different decision variables must include this fact. This is especially important for models that are aimed to be used for practical purposes. When influential observations are present and have an unacceptable effect on the least squares method, the best remedy is to apply a robust estimator rather than deleting these observations. OLS regression models are quite sensitive to influential observations, which may be a consequence of heavy-tailed distributions. Hampel (1985) argues that robust estimators are superior in practice to classical non-robust estimators and shows that they are even better than classical methods combined with rejection. Huber (1964) proposed as a robust estimator (the maximum-likelihood estimator) of the location parameter associated with a density function that is normal in the middle part, but like a double exponential in the tails. In our analysis, we apply a bounded-influence technique proposed by Schweppe (Handschin et al., 1975). This technique reduces the impact of influential observations in both y-space as well as x-space. However, different variables have different characteristics. Some of the variables take non-negative values while other variables may be either negative, zero or positive. Depending on the nature of the dependent variable we combine four different robust estimation methods: Huber-Schweppe robust estimation method, a logistic model with the cumulative logistic distribution function, a logistic model with the complementary log-log distribution function, and a Tobit model with a logistic distribution function.

The estimation results indicate that firms’ utilization of different tax allowances as well as different accounting constraints have important impact on firms’ investment and financial behaviour. These results indicate that estimation of behavioural factors has an important role in assessing the financial implications of proposals for change in the tax code and accounting rules. This was originally observed in Forsling’s (1998) study of the utilization of different tax allowances.

3. Description of data

In 1997, the Ministry of Finance and Statistics Sweden (SCB) started developing FRIDA, which stands for Firm Register and Individual DAtabases. FRIDA is composed of several databases for firms with different organization forms. This includes databases for joint stock companies (which also includes closed companies), cooperatives, partnerships (which also includes limited partnerships), associations, foundations, and proprietorships (or sole traders). Apart from partnerships and proprietorships, these enterprises are subject to corporation tax. In this paper, we will present the database for stock companies which is used in the simulation model. The information gathered for these firms includes accounts, balance sheets, wages and other compensation, depreciation, untaxed reserves and dividends, etc. Moreover, it also includes information on tax adjustments.

The data at our disposal come mainly from the National Tax Board (RSV) and include the Standardized Accounting Statements (SRU) and the Tax Assessment (TA). The SRU contains information on accounts and tax adjustments and the TA contains information on the income tax paid by the firms. The TA files contain pure information on assessed income, preliminary tax, final tax, and some administrative data. However, the TA data do not contain any background information on how the final tax is calculated (accounts, balance sheet and tax adjustments). Both the TA and the SRU files are designed to cover the total population of firms. We chose to have 1997 as a base year for our database as the quality of the data were better from this year. The sampling frame for the database is based on register data in TA and SRU. For the joint stock companies, we select those firms that provide the income tax return form S2. This register is then supplemented with further information about the organization form from SCB’s Central Register of Enterprises and Establishments. The sampling frame is then adjusted by removing the income tax return form for those firms that have provided two identical forms. The stratification is made according to company size and whether they are a close company. For this purpose, we select those firms that complete their income tax return forms with another form (K10) that is used by shareholders in close companies. The firms’ size is based on total assets (K), net income (NI), and net business income (NBI). The sampling frame is stratified in three different strata.

The first stratum contains each and every financial firm that has the industry classification 65, 66, and 67 according to the Swedish Standard Industrial Classification 1992 (SNI92). This classification standard is based on the classification used by Eurostat, NACE Rev. Further, this stratum also contains all those firms that fulfil the following conditions: Total assets (K) are higher than 100 MSEK, net income (NI) is higher than 5 MSEK (which is the case for both positive and negative net income), and net business income (NBI) is higher than 5 MSEK (which is the case for both positive and negative net business income). Remaining firms are classified between two different strata depending on whether there is a K10 form assigned to the company. In the first stratum, all units are selected. In the other two strata, the numbers of units drawn are a function of NBI. For this purpose a simple random sampling (SRS) was used. The idea behind the database is to gain a fairly good approximation of the total net business income and final tax payments.

In our estimations, we use the information from 1997–1999. For these years, we have two time series observations on different variables for each and every firm. For 1997–1999, we have 27 370, 27 440, and 35 457 cross-sectional observations respectively (see Table 1). This gives us a total of 90 227 pooled observations. The sample sizes were originally bigger (column 3 in Table 1). However, these samples were checked for inconsistencies and errors. Observations that did not fulfil the constructed criteria were excluded from the original samples (column 4 in Table 1). Moreover, for estimation purposes, we also need two time series observations on different variables. Therefore, we exclude those firms that did not provide information the previous year (column 5 in Table 1). We obtain a smaller sample size by doing so. The samples were then re-weighted.

Check for inconsistencies and errors

As we mentioned earlier, the original sample for each and every year is checked for inconsistencies and errors. We regard those firms that do not pass through the error and correction program as outliers and exclude them from our sample. The sample is then re-weighted. The data program for auditing and correction contains 30–60 modules. The structure of auditing and correction is as follows. First, the program starts by controlling whether the observations lack balance sheet data, income statement data, or tax adjustments. Although the firms are under a statutory obligation to supply the data, non-response does occur. We do not use imputation methods to handle the non-response. Instead, we regard these firms as outliers and exclude them from our sample. Second, the balance sheet, income statement, and tax adjustments undergo a detailed examination by the program developed. Routines for testing and improving the data quality have been developed to make the SRU and TA files reliable. Usually the errors originate from the following: clerical or typing errors, summation errors, or changes in the assessment of tax that is not registered in SRU files. In each module, we check whether firms have made a correct addition of the information requested by the tax authorities. If the deviation is lower than 100 SEK, we accept the addition made by firms. If not, we correct the information. All corrections are made automatically to avoid costly revision.

Table 1. A description of the sample for 1997, 1998, and 1999.
Year Sampling frame Initial sample size Initial sample size correction* Sample size after data Sample size with observations for t-2
1997 2,56,171 33,887 29,363 27,370
1998 2,50,058 35,107 31,400 27,400
1999 2,43,131 36,566 36,238 35,457
Total 7,49,360 1,05,560 97,001 90,227

After the sampling, we check for inconsistencies and errors. If the firm does not fulfil the constructed criteria, it is regarded as an outlier and excluded from the sample. The sample is then re-weighted.

Table 2. Simulation results using current rules, MSEK.
2000 2001 2002 2003 2004
Assets
 CA 21,57,244 26,26,464 29,91,256 32,85,191 35,76,919
MA 6,55,068 7,37,831 8,12,583 8,85,209 9,56,082
BU 5,26,931 10,34,464 12,55,277 13,23,282 13,87,825
OFA 36,97,248 33,25,529 34,41,718 36,46,573 36,58,999
Total 70,33,491 77,24,288 85,00,834 91,40,255 95,79,825
Liabilities
CL 14,81,818 26,98,440 34,49,106 38,42,111 42,31,449
LL 26,07,697 27,29,837 28,33,233 39,17,740 30,00,933
ASD 2,28,662 2,35,496 2,40,215 2,44,820 2,48,510
OUR 10,524 10,760 10,939 10,987 11,138
SC 3,38,181 3,61,574 3,84,821 4,06,226 4,29,033
RR 6,14,792 8,69,063 11,24,540 13,77,906 16,31,679
URE 15,58,227 5,92,813 2,01,132 50,403 −2,93,084
PFt 1,93,585 2,26,301 2,56,844 2,90,058 3,20,165
Total 70,33,486 77,24,284 85,00,830 91,40,251 95,79,823
Income statement
OIBD 2,80,257 4,05,649 4,16,275 4,09,780 4,17,883
EDEPma 1,04,559 1,28,439 1,32,789 1,31,337 1,32,571
EDEPbu 9,084 20,342 19,701 18,767 18,602
OIAD 1,66,613 2,56,867 2,63,784 2,59,675 2,66,709
EBA 1,84,907 2,50,162 2,69,569 2,74,013 2,81,933
EBT 1,44,302 2,20,969 2,45,122 2,47,502 2,63,326
NI 90,460 1,80,345 2,00,673 1,95,417 2,11,841
FTAX 47,735 42,842 42,689 42,980 43,766
Olt 4,10,084 4,88,375 5,46,493 6,06,410 6,52,192
NBI 96,566 1,78,126 2,02,432 2,04,522 2,19,559
Selected flow variables and financial ratios
CR 1.456 0.973 0.867 0.855 0.845
DR 0.599 0.720 0.756 0.756 0.772
DER 1.492 2.570 3.094 3.103 3.384
ECR 0.401 0.280 0.244 0.244 0.228
FQ −0.292 −0.380 −0.404 −0.397 −0.399
ICR 1.493 .634 1.682 1.684 1.693
DI 0.089 0.071 0.062 0.058 0.055
ROE 0.097 0.097 0.108 0.100 0.105
ROI 0.080 0.083 0.078 0.074 0.072
EFFTAX 0.258 0.171 0.158 0.157 0.155
RROI 0.072 0.062 0.059 0.061 0.062
ER 0.007 0.022 0.019 0.013 0.010

Notes: See Appendix 1 for key to variable names

4. The simulation results using current tax rules

Table 2 summarizes the simulation results from 2000–2004 that were obtained by solving the difference equation systems numerically. Let us now penetrate some of the most important results. Firms’ operating income before depreciation (OIBD) increases between 2000 and 2002. In 2003, this increase continues. This variable shows a large increase between 2000 and 2001. The reason for this is that OIBD is estimated to increase with the level of current assets (CA), the level of machinery and equipment (MA), the net investment in machinery and equipment (IMA), economic depreciation of machinery and equipment (EDEPMA) at a decreasing rate, the level of buildings (BU), the net investment in buildings (IBU), economic depreciation of buildings (EDEPBU) at an increasing rate, the net change in current assets (dCA) at a decreasing rate, the change in the utilization of tax rules regarding allocations to periodical reserves (ddmpa) at a decreasing rate the increase is decreasing, and the change in cash flow (dcashfl) at an increasing rate. These variables are also estimated and simulated to increase during the simulation period mainly because of the macroeconomic development. Despite the fact that OIBD increases in 2001, final taxes paid (FTAX) by the firms decreases. This has to do with the development of tax adjustments made by the firm. This is especially the case for losses from previous years (OL) which increase during the entire simulation period. The development of OIBD is important for the development of earnings before allocations (EBA) which increases as OIBD increases. This together with the development of FTAX imply that the effective tax rate (EFFTAX) decreases in 2001 and continues to decrease during the simulation period.

We use financial ratio analysis to summarize the simulation results. Four major categories of financial ratios have been developed, each designed to address an important aspect of the firms’ financial condition: liquidity ratios, leverage ratios, profitability ratios, and market value ratios (see Appendix 3). Corporate debt in relation to total assets (DR) is simulated to grow rapidly during the simulation period. This is believed to be due to the strong credit growth in the corporate sector. This indicates that the extent to which firms use borrowed funds to finance their total assets increases. The debt/equity ratio (DER) also increases during the entire simulation period, which indicates that the capital contributed by creditors increases compared to the capital contributed by owners. However, the interest coverage ratio (ICR) increases during the entire simulation period indicating that firms’ ability to meet their interest payments out of their operating earnings improve over coming years. But, companies’ current ratio is simulated to gradually deteriorate, which means that companies have diminishing liquid assets to use for their short-term payment commitments. The worsened current ratio does not pose any problem that companies will be unable to meet their payment commitments as long as companies’ earnings capacity and profitability remain sound. As is evident from the simulation results, companies increase their profitability (ROI) during 2001, after which it decreases from 2002–2004. Return on investment focuses on the earnings power of ongoing operations. This return must be compared to the required return on investment (RROI) to be able to draw conclusions about the value of TOBINS q. Excess return increases in 2001 before it decreases three years in a row. This indicates that return on investment is constantly reduced relative to the required return on investment. This in turn implies that the value of TOBINS q becomes lower and lower, indicating that the value of the firms compared to the replacement costs of the firms’ assets decreases. Hence, the market’s prediction of the value of the returns generated per 1 SEK of additional investment becomes lower.

Table 3. Forecasting accuracy for year 2000.
Variable name Population weighted, Year 2000, MSEK Matched pairs t-test*** (t)
Sample Predicted
Mean (A) Standard deviation (B) Mean (C) Standard deviation (D)
EDEPMA 0.447 15.150 0.458 10.439 −0.280
SMA 2.206 1097.177 0.092 50.235 0.920
IMA 2.945 1096.308 0.834 10.150 0.920
EDEPBU 0.069 1.821 0.039 1.251 6.233
IBU 0.161 29.319 0.029 7.808 2.083
dofa −2.600 2373.374 2.671 87.504 −1.061
dca 0.417 578.716 0.546 26.748 −0.106
dll −3.446 2104.863 0.283 23.357 −0.847
dcl 0.114 432.930 −0.502 30.057 0.678
dsc −0.035 48.833 0.090 5.457 −1.217
drr 0.456 113.333 1.157 12.723 −2.937
OIBD 1.398 81.459 1.227 17.734 0.980
FI 1.880 153.795 .722 103.292 0.407
FE 1.150 55.330 1.641 112.435 −1.875
TDEPMA 0.538 18.430 0.522 6.936 0.408
ZPF 0.095 8.401 −0.001 0.444 5.485
Dour −0.015 2.216 0.087 8.181 −5.775
GC 0.033 45.076 0.032 35.622 0.008
OA 0.068 42.842 0.072 35.470 −0.041
TL 0.233 7.468 0.236 37.691 −0.041
OTA −0.678 147.590 −0.221 19.762 −1.465
TDEPBU 0.086 3.688 0.080 1.308 0.668
PALLO 0.224 32.200 0.274 2.580 −0.733
ROT 0.002 4.355 0.091 7.970 −1.007
TAX 0.212 6.360 0.230 2.168 −1.270
FTAX 0.210 6.000 0.209 8.168 0.060

Notes: See Appendix 1 for key to variable names

Calculated by dividing weighted sum of variable in the sample by population size

Calculated using the population rather than sample size

The match pair t-test of equal predicted and sample means is performed as follows: t = (A-B)/sqrt(C**2/N)+D**2/N) where N = 228344 is the population size.

5. The forecasting accuracy

In Table 3, we present a matched pairs test of the hypothesis that the weighted mean of different variables in the sample for the year 2000 coincides with the predicted mean for the same variables. The table shows that t-values for these variables lie within the acceptance region with the exception of EDEPtBU, drrt and dourt. The most crucial variable in the simulation model is the sum of the corporate taxes that firms pay to the government. The sum of taxes paid by all firms, in 2000, equals 48 026 MSEK. Our simulated tax payment for 2000 is 47 735 MSEK. The difference is 291 MSEK, which indicate an underestimation of the tax payments by 0.6 per cent. Table 3 reinforces the forecasting accuracy of the firms’ tax payments when we use both the information about the mean and the standard deviation. The matched pairs test indicates that we cannot reject the hypothesis that the weighted mean of tax payments in the sample for the year 2000 coincides with the predicted mean for the same variable.

Table 4. The actual and predicted distribution.
The actual distribution The predicted distribution
Mean 2,02,425.364 2,20,221.588
Standard Deviation 1,60,57,919.6 2,29,66,100
Skewness 51.3292645 −155.64327
Curtosis 3,517.11279 25,481.8173
100% Max 1,38,01,03,929 39,02,61,309
90% 1,76,232 4,37,049
75% Q3 43,411 2,71,427
50% Median 4076 1,82,961
25% Q1 0 0
10% 0 0
0% Min 0 −3702063348

Another way of evaluating the forecasting accuracy is to compare the distribution of predicted tax payments with the actual distribution. This is done by looking at the mean, the standard deviation, the skewness, the kurtosis, and the median of the distributions (Table 4). As can be seen, the predicted distribution is more skewed on the left side and more tapering compared to the actual distribution. It is also evident that the median of the predicted distribution is much higher than the median for the actual distributions. Moreover, there are negative simulated final taxes (FTAX) which may be due to the following. To be able to derive firms’ final tax payments (FTAX), we adjust firms’ tax payments (TAX) for their reduction of taxes (ROT) so that FTAX = TAXROT. We impose a nonnegative constraint on TAX as follows: TAXt = τ max[0,(NIt + TAt)] where τ is the corporate tax rate, TAt (which either can be positive, negative or equal to zero) is the firms’ tax adjustments. However, we do not impose non-negative constraint on FTAX because firms can obtain tax refunds due to a reduction in taxes (ROT). But, we found out that ROT was very difficult to estimate and simulate because of the appearance of data errors and outliers. We have obviously simulated a very high reduction of taxes which in turn generates a negative value for FTAX. One way to overcome this problem is to also impose non-negative constraint on final taxes. Finally, while 10 percent of companies are paying more than around 180 000 kronor, we simulate that 50 percent of the companies will pay more than this amount in final taxes. This evaluation exercise shows that only general tax rule changes should be applied in this model. This has to do with the fact that the method used to estimate different variables is a non-parametric estimation method that gives different weight to different observations. This means that small, medium and large companies are weighted up or down in relation to an average “medium” enterprise. This is why we cannot replicate the distribution of FTAX. One way around this problem is to estimate the behaviour of small, medium and large companies instead of estimating the behaviour of all companies. However, this is very time-consuming. After all, it should be borne in mind that a simulation model must be updated each year as new data bases become available.

At present, the selection of the sample is a function of corporate final tax payments (FTAX). In other words, the sample is drawn so that the ratio of the weighted sum of the final taxes in the sample and the sum of the final taxes in the total population will come close to unity. For 1999 and 2000 this ratio equals 1.03 and 1.04 respectively. However, for other variables, we are aware that it is very uncertain whether this ratio will come close to unity. Even more important is the fact that the ratio may change significantly between sampling years. For example, precision ratio of investment in machinery and equipment (IMA) in 1999 is close to 1, indicating a good precision. On the other hand, the ratio is more than three times higher in 2000. A comparison of the precision ratio for IMA in 1999 and 2000 indicates that the selections of the samples for 1999 and 2000 are not comparable. Another way to interpret these results is that the sample (in the case of variable IMA) is randomly drawn in 1999 while the selection for 2000 is not a random sample. This makes it almost impossible to evaluate the model in terms of other variables (i.e. the 24 estimated decision variables in the simulation) than final taxes (FTAX).

Table 5. Simulation results for a proposed tax reduction by 3 per cent, MSEK.
2000 2001 2002 2003 2004
Final taxes paid
FTAX 47,735 42,842 37,651 37,888 38,581
Financial ratio analysis
CR 1.456 0.973 0.867 0.855 0.845
DR 0.599 0.720 0.754 0.754 0.770
DER 1.492 20570 3.064 3.073 3.350
ECR 0.401 0.280 0.246 0.246 0.230
FQ −0.292 −0.380 −0.402 −0.395 −0.397
ICR 1.493 1.634 1.682 1.684 1.693
DI 0.089 0.071 0.062 0.058 0.055
ROE 0.097 0.097 0.108 0.099 0.105
ROI 0.080 0.083 0.078 0.074 0.072
EFFTAX 0.258 0.171 0.140 0.138 0.137
RROI 0.072 0.062 0.058 0.059 0.060
ER 0.007 0.022 0.020 0.015 0.012
The cost of the proposed tax rule
Periodic net cost (FTAXPFTAXC) 0 0 −5038 −5092 5185

Notes: See Appendix 1 for key to variable names

6. Simulation results for a hypothetical corporate tax rate reduction of three percent

To illustrate the application of our model, in this section we present a simulation exercise, in which the statutory corporate tax rate is reduced by 3 per cent (from 28 per cent to 25 per cent) from 2002. This is only a hypothetical simulation exercise and does not refer to a government proposal.

The best way of analysing the implication of the new rules for the corporations is to compare the development of weighted average financial ratios for current tax rules (Table 2) with the development of the financial ratios for a hypothetical corporate tax rate reduction of three per cent (Table 5). The reduction of the tax rate by 3 per cent implies that the final taxes paid by the firms (FTAX) decreases. The cost of the proposed tax rule is about MSEK 5 038 in 2002, MSEK 5 092 in 2003, and MSEK 5 185 in 2004 (see Table 5). The decrease in FTAX implies that the effective tax rate (EFFTAX) decreases from 15.8 per cent to 14.0 per cent in 2002, 15.7 per cent to 13.8 per cent in 2003, and 15.5 per cent to 13.7 per cent in 2004. An interesting observation is that a decrease in the statutory corporate tax rate by 3 per cent only decreases the effective taxes paid by the firms by about 1.8 per cent. It is the effective tax rate which is important for corporate investment and financial decisions. The lesson from this simulation exercise is that if the statutory corporate tax is reduced to stimulate corporate investment, one should bear in mind that the impact may be lower than expected because firms have the opportunity to adjust their utilization of the tax rules, and their financial behaviour. Behavioural factors play an important role in assessing the financial implications of proposals for change in the tax code.

The current ratio is not affected by the new rule. This means that the new tax rule does not have any impact on firms” ability to meet their short-term obligations, which means that the tax change does not improve the liquidity position of firms. The new tax rule causes a small decrease in the weighted average debt ratio. The tax decrease has a small impact on the extent to which firms use borrowed funds to finance their total assets. The required return on investment decreases because of the tax decrease, and hence the weighted average excess return increases. This indicates that the value of TOBINS q becomes higher, which in its case indicates that the value of the firms compared to the replacement costs of the firms” assets increases. This means that the proposed tax reduction will have a positive impact on corporate investment.

7. Simulation results for ahypothetical change in the macro economic developments

The simulation results for a hypothetical change in the macro economic developments are summarized in Table 6. In this case, we compare the macroeconomic development forecast presented in government’s budget bill for 2000 with the macroeconomic development forecast in the government’s spring fiscal policy bill in 2000 (see Table 7). An interesting observation is that the forecasts was not revised so much in the spring bill except for GDP growth for 2001 and 2002 which were revised downwards by 1 and 0.7 percentage points respectively.

The best way of analysing the implication of the new macro-economic development for firms is to compare the development of weighted average financial ratios for the initially assumed macro economic development (Table 2) with the development of the financial ratios for the new macro-economic development (Table 6). In the new macroeconomic environment, the government receives higher taxes from firms during 2000. However, from 2001, firms” tax payments to the government (FTAX) decrease. This is a natural consequence of the lower GDP growth forecast in the government’s spring fiscal policy bill in 2000. However, the effective tax rate (EFFTAX) is almost the same even when firms” tax payments to the government decrease during the simulation period.

Table 6. Simulated results from an alternative macroeconomic development, MSEK.
2000 2001 2002 2003 2004
Final taxes paid
FTAX 48,642 41,072 39,760 39,984 40,807
Financial ratio analysis
CR 1.339 1.064 0.998 0.972 0.933
DR 0.627 0.700 0.724 0.734 0.762
DER 1.682 2.337 2.620 2.574 3.196
ECR 0.373 0.300 0.276 0.266 0.238
FQ −0.310 −0.357 −0.366 −0.365 −0.376
ICR 1.511 1.590 1.642 1.652 1.666
DI 0.086 0.074 0.066 0.062 0.058
ROE 0.082 0.082 0.090 0.089 0.101
ROI 0.081 0.082 0.078 0.075 0.073
EFFTAX 0.253 0.178 0.160 0.156 0.153
RROI 0.072 0.063 0.062 0.062 0.061
ER 0.009 0.109 0.016 0.013 0.012
The cost of the proposed tax rule
Periodic net cost (FTAXPFTAXC) 907 −1770 −2929 −2996 −2959

Notes: See Appendix 1 for key to variable names

Table 7. Macroeconomic forecast in the government’s budget bill and spring fiscal policy bill (in parenthesis), SEK billion, percentage change, and percent.
1999 2000 2001 2002 2003 2004
GDP 2010 (2010) 2083 (2098) 2118 (2115) 2169 (2151) 2225 (2207) 2277 (2262)
dGDP 79 (79) 72 (88) 35 (16) 51 (37) 56 (55) 51 (56)
dlGDP 3.60 (4.38) 1.70 (0.77) 2.40 (1.73) 2.60 (2.58) 2.30 (2.52)
r10* 4.83 (4.83) 5.40 (5.37) 5.20 (5.10) 5.20 (5.00) 5.20 (5.11) 5.20 (5.20)
Inflation 1.20 (1.20) 1.40 (1.30) 2.70 (2.60) 1.80 (2.10) 2.00 (2.20) 2.00 (2.00)
Real r10 3.59 (3.59) 3.94 (4.02) 2.43 (2.44) 3.34 (2.84) 3.14 (2.85) 3.14 (3.14)

Notes: See Appendix 1 for key to variable names;

r10 is the nominal interest rate on a government bond with a maturity of 10 years.

The current ratio decreases, which means that the new macro economic development degrades firms” abilities to meet their short-term obligations. This means that the new macro economic development impairs the liquidity position of firms. The new macro economic development causes a small decrease in the debt ratio which indicates that the new macro economic development has a small impact on the extent to which firms use borrowed funds to finance their total assets.

Conclusions

The basic idea behind the simulation model is to combine the dynamic behaviour of the corporate system with a statistical model that captures the development and the interrelationships between the firms’ different decision variables. The dynamic behaviour of the corporate system is captured by several difference equations that identify how different variables in the firms’ balance sheets change over time using the information in the firms’ three basic financial statements: the balance sheet, the income statement, and the statement of changes in financial conditions. The firms’ decisions regarding the flow variables are modelled in a statistical module. From the dynamic optimization problem we derive the relationships between these flow variables. These relationships are then estimated using different robust estimation methods. The estimated functions from the statistical module are then inserted into the difference equation system. The difference equation system together with the estimated relationships is finally solved numerically to be able to simulate new financial statements. Tests indicate that the model’s ability to predict firms’ final tax payments as well as other variables is satisfactory.

We pointed out that estimation of behavioural factors plays an important role in assessing the financial implications of proposals for a change in the tax code. Moreover, we also pointed out the importance of using robust estimation methods. The reason for using robust estimations methods is because microdata on firms often reveal that influential observations are present. The estimation method that is used to estimate firms’ behaviour regarding different decisions variables must be able to deal with this fact. OLS regression models are quite sensitive to influential observations, which may be a consequence of heavy-tailed distributions. The estimation results using robust estimation methods revealed that firms’ utilization of different tax allowances as well as different accounting constraints have an important impact on firms’ investment and financial behaviour.

The lesson from this simulation exercise is that if the statutory corporate tax is reduced to stimulate corporate investment, one should bear in mind that the impact may be lower than expected because firms have the opportunity to adjust their utilization of the tax rules, and their financial behaviour. Behavioural factors play an important role in assessing the financial implications of proposals for changes in the tax code.

This is also confirmed by the simulation results which indicate that the cost of a proposed corporate tax rate reduction increase over time. The simulation results also indicate that a statutory corporate tax rate reduction does not decrease the effective corporate tax rate equally. This is mainly because firms have the opportunity to adjust their utilization of the tax rules and their financial behaviour to the new tax rules. Moreover, the simulation results also indicate that a corporate tax change has a significant impact on the extent to which firms use borrowed funds to finance their total assets, the capital contributed by creditors compared with the capital contributed by owners, and the market’s prediction of the value of the returns of additional investment.

Finally, the simulation model gives us the opportunity to examine the impact of combined changes of the macroeconomic variables. The simulation results indicate that macroeconomic developments have major impact on corporate taxes paid by the firms. However, it is not obvious that the effective tax rate for these firms will change dramatically because of the changed macro conditions. This is due to the fact that firms have the opportunity to adjust their utilization of the tax rules and their financial behaviour and thereby adjust their effective tax rate.