Tax Evasion problem

I attempting to make a policy which will lower Tax Evasion among other things. While the influence on groups is working out just fine, when I attempted to put “TaxEvasion,-0.02-(0.2x)" under the effects (numbers somewhat randomly picked), the game would crash when loading a country. Being the clever girl I am I decided to put "TaxAudits,-0.02-(0.2x)” instead. Though the game no longer crashed, all situations were now mysteriously gone…After backing up to the old Situations file and re-adding the TaxAudits line, all was well. However, when implementing the policy in a nation which has Tax Evasion, it doesn’t appear to actually influence Tax Evasion at all. What am I doing wrong?