The gender wage gap is one of the most persistent problems of labor markets and women's lives. Most approaches to explaining the gap focus on adult employment despite the fact that many Americans begin working well before their education is completed. In her critical and compelling new book, The Cost of Being a Girl, Yasemin Besen-Cassino examines the origins of the gender wage gap by looking at the teenage labor force, where comparisons between boys and girls ought to show no difference, but do.Besen-Cassino's findings are disturbing. Because of discrimination in the market, most teenage girls who start part-time work as babysitters and in other freelance jobs fail to make the same wages as teenage boys who move into employee-type jobs. The "cost" of being a girl is also psychological; when teenage girls work retail jobs in the apparel industry, they have lower wages and body image issues in the long run.Through in-depth interviews and surveys with workers and employees, The Cost of Being a Girl puts this alarming social problem-which extends to race and class inequality-in to bold relief. Besen-Cassino emphasizes that early inequalities in the workplace ultimately translate into greater inequalities in the overall labor force.