THE INFLUENCE OF CHANGES IN PERSONAL INCOME TAX REGULATIONS ON DONATING NON-PROFIT ORGANIZATION Summary

Each entity paying taxes would like to have real influence on the way of their allocation. Since 2004 in Poland payers of personal income tax were able to decide about donating 1 percent of personal income tax to a chosen public benefit organization for the first time. Since the introduction of the possibility of donating non-profit organization (NPO) tax regulations were repeatedly modified. Did tax-payers willingly use the ability to decide who they should donate their 1 percent of personal income tax to? In what way did changes of tax regulations influence taxpayers ’ decision? In order to answer those questions soft modelling was used, which allowed to examine the influence of changes in regulations relating to 1 percent of personal income tax on taxpayers ’ decision. Key words: taxpayers ’ behaviuor, changes in tax regulations, 1 percent ta