This thesis explores the integrative effect of social psychological factors among themselves as well as with economic deterrent factors in stimulating voluntary tax compliance, contributing to the tax compliance literature a theoretically relevant integrative approach that bridges between social psychological and economic deterrence approaches. It also contributes to the ecological validity of research on tax compliance behavior by comparing samples of two tax environments that are extremely unlike—one from a developing country (i.e. Ethiopia) and another from a developed country (i.e. the US). Chapter 1 is an introductory chapter that seeks to introduce the thesis and summarize research on voluntary tax compliance, highlighting the need...