China suffers from enormous gender imbalance: there are many more boys than girls. Part of this is due to selective abortion, and part is due to worse treatment of girls. Nancy Qian was interested in finding out whether parents consider the future possible wages of a girl when deciding how much to feed them and take care of them. To this end, she exploits the reform that brought household responsibility system reform in China. After Den Xiao Ping replaced Mao in 1979, households were given the choice about what crop to grow (before, they essentially had to grow cereals), and suitable regions started producing tea and orchards. Women are particularly useful for tea growing, which requires nimble hands. Therefore she proposed that parents would start taking better care of girls in regions that produce tea. Girls would be more likely to survive, and this would translate into a relatively lower share of males in those region after the reform, thus justifying a difference in difference approach. Let POST be a dummy for post reform, and T'BA be a dummy for whether the region produces tea. Let Y' be the fraction of boys in region i at time t She runs the following regression: Yit = Bo + 8,TEA; + 8, POST, + A; POST, . TEA; + ex Question 17 0.0/1.0 point (graded) This question has 3 parts: Given the regression she runs, which of the following denotes the the average fraction of males in tea-regions, pre-reform? O Bo O By O Bo + BI O B + 2 O B2 + B3