Numerous regulations and tax changes are making income tax returns increasingly complex and non-transparent. Reports of other people’s uncertainty about declaring their taxable income can undermine taxpayers’ individual tax morale. They become more lenient towards tax evasion as the tax problems of others become more understandable. This effect is even stronger for older people and those with a more left-wing political orientation, according to a study by ZEW Mannheim. For the study, more than 4,000 German citizens were interviewed in a representative survey.