Using newly collected and existing data and modern econometric approaches, this book analyses the gender wage gap as well as less explored dimensions of discrimination such as religion, sexual orientation, and physical appearance. Part One focuses on gender. Using a newly collected database for Italy, it analyses the relevance of transition from school to work, and in particular the choice of college major, in determining the gender earning gap. It also analyses the role of family and of discrimination on the job as a potential source of this gap, using additional data from Spain and the US. Part Two analyses different forms of discrimination towards individuals in the labor market. In particular, it examines the potential for discrimination of sexual orientation, religion, and physical appearance and weight. The analysis is conducted by means of a survey of the existing literature and by an empirical analysis, using European data as well as Italian data collected through an experimental design.