This will be a log of changes to Internet Taxsim Version 5. The sources of suggestions/bug reports are given in parenthesis. Remember to include a small example (just a couple of records) with any bug reports, which may be sent to feenberg at Version 5.1 April 20th (Don Bruce) For states allowing separate filing by husbands and wives, non-wage income is now allocated evenly between spouses. Previously it was allocated in proportion to wages, if both had wages and one-third-two-thirds if not. That caused marginal tax rates to explode in some circumstances. March 24th (Adam Looney) Correct 4 digit dependent counts to prevent crashes. March 8th (Alex Bal) Fix Arkansas problem not respecting compulsory itemzation command. February 10, 2004 (Jesse Rothstein) Fix earned income credit phaseout to subtract from maximum credit rather than rate*base. February 10, 2004 (Alex Bal) Fix bracket rate calculation for states with optional separate filing and problems with state=-1 and wage marginal tax rate. September 15, 2003 (Ed Harris) Correct taxation of pensions in AR and MA in all years. August 23, 2003 ( Fix implausible marginal rates caused by choosing itemization status based on size of itemized deductions, rather than size of tax for Arkansas, Delaware, DC and Kentucky. August 5 ( Remove maximum tax on earned income from 1965-1970 period. Fix to rate of .6 rather than .5 for 1971. July 18 Fix personal exemption phaseout 2002-2005. June 24 ( Add capital gains tax rate calculation. Fix marginal tax output for state equal -1. Fix detailed reports to not misreport anachronistic items. Give low rate to all dividends under JGTRRA June ( Modify 2003-2010 federal code to include JGTRRA legislation passed in April of 2003. Fix FICA calculation for 2004 on. Changes in Version 5 March 17th, ( Fix marginal rate detail for General Tax Credit and Maximum Tax on Earned Income. January 27, 2003 (Allan Crego) We change the calculation for married/separate in the 11 states that allow separate filing for married couples on a single return: 1) Wage income is assigned to the husband or wife according to the data. 2) Non-wage income, exemptions and deductions are assigned 50/50. 3) The program selects the lower taxed filing status (joint or separate). Item (2) is a bit arbitrary, but I don't think we can do unambiguously better since optimal allocation of other income requires the suspension of "marital distrust". The earlier approach of assigning all income and deductions in proportion to wages causes wild marginal rate swings when wages are close to zero. Major Changes since version 4: Federal tax extended to 2010, states to 2001. Offer comprehensive analytical calculation of the marginal rate of tax on wage income. Double precision calculation, with marginal rate based on ten-cent finite difference. FICA tax calculation Detailed intermediate results of tax calculation (optional) Decision to itemize is based on tax-minimization rather than taxable income minimization (significant for some AMT taxpayers). Marginal rates are not corrupted by changes in itemization status during the calculation of marginal rates. Child Tax Credit (Marina D. Azzimonti Renzo). Add a way to specify the number of children eligible for the CTC.