Carlo D’Ippoliti is a research fellow of economics at Sapienza University of Rome, Italy.

• Preface Marcella Corsi and Bertram Schefold. Introduction Part 1: There is Difference in Difference: Diversity and Heterogeneity 1. The Night in Which All Cows are Black 2. Lessons from the Past Part 2: Difference, Behavior and Aggregative Analysis 3. Social Sciences and the Act of Classification 4. Individual and Aggregate Behavior 5. Consequences for Economic Theory and Method Part 3: On Gender Diversity 6. Gender Diversity as Inequality 7. Schmoller on the Origin of Gender Inequality 8. Mill and the Liberal Stance 9. The State, the Market, and Gender Part 4: An Application: Gender Diversity in the Labor Market 10. Gender, Diversity and Heterogeneity in the Labor Market 11. How Gender may Help in Understanding the Labor Market 12. How Economcis May Help in Understanding Gender 13. Analysis of Men’s and Women’s Employment. Appendix. Conclusions

Carlo D’Ippoliti is a research fellow of economics at Sapienza University of Rome, Italy.

• Preface Marcella Corsi and Bertram Schefold. Introduction Part 1: There is Difference in Difference: Diversity and Heterogeneity 1. The Night in Which All Cows are Black 2. Lessons from the Past Part 2: Difference, Behavior and Aggregative Analysis 3. Social Sciences and the Act of Classification 4. Individual and Aggregate Behavior 5. Consequences for Economic Theory and Method Part 3: On Gender Diversity 6. Gender Diversity as Inequality 7. Schmoller on the Origin of Gender Inequality 8. Mill and the Liberal Stance 9. The State, the Market, and Gender Part 4: An Application: Gender Diversity in the Labor Market 10. Gender, Diversity and Heterogeneity in the Labor Market 11. How Gender may Help in Understanding the Labor Market 12. How Economcis May Help in Understanding Gender 13. Analysis of Men’s and Women’s Employment. Appendix. Conclusions

Carlo D’Ippoliti is a research fellow of economics at Sapienza University of Rome, Italy.

• Preface Marcella Corsi and Bertram Schefold. Introduction Part 1: There is Difference in Difference: Diversity and Heterogeneity 1. The Night in Which All Cows are Black 2. Lessons from the Past Part 2: Difference, Behavior and Aggregative Analysis 3. Social Sciences and the Act of Classification 4. Individual and Aggregate Behavior 5. Consequences for Economic Theory and Method Part 3: On Gender Diversity 6. Gender Diversity as Inequality 7. Schmoller on the Origin of Gender Inequality 8. Mill and the Liberal Stance 9. The State, the Market, and Gender Part 4: An Application: Gender Diversity in the Labor Market 10. Gender, Diversity and Heterogeneity in the Labor Market 11. How Gender may Help in Understanding the Labor Market 12. How Economcis May Help in Understanding Gender 13. Analysis of Men’s and Women’s Employment. Appendix. Conclusions