The Promise of Freedom: Fertility Decisions and the Escape from Slavery
利用1850年《逃奴法》的地理差异，发现奴隶女性生育率与距自由距离呈负相关，且该效应在大种植园更强、女奴隶主时更弱，说明自由承诺影响奴隶日常决策。
This paper examines how the fertility of enslaved women was affected by the promise of freedom. Exploiting geographic variation in the effect of the Fugitive Slave Law of 1850, I demonstrate a negative correlation between fertility and the distance to freedom. This negative correlation is stronger on larger plantations but weaker when the slaveholder is a woman. A similar correlation is not present for white children, slave children with white fathers, or slave children born prior to the Fugitive Slave Law. The negative correlation suggests that the promise of freedom played an important role in the everyday lives of slaves. © 2015 The President and Fellows of Harvard College and the Massachusetts Institute of Technology