Primary focus of my Bachelor`s Thesis is how taxes affect size of shadow economy. Beginning of my thesis consists of different opinions of prominent economists, public figures and journalists about the Phenomena. I am discussing how those opinions are sometimes similar and sometimes totally different depending on viewpoint and timescale.In Theoretical Part Illicit activities are analysed thru lenses of welfare economy. I am looking at Short run and Long run consequences of increasing Shadow Economy and analyse positive and negative aspects of Illicit activities on wealth of states and its inhabitants. Using Economic Psychology, I am identifying Internal and External Sources that are affecting individual’s decision process including but not ...