1. Peer Effects on GPA Robyn Meikle and Joyce Silver

2. Difficulties Measuring Peer Effects  Self-selection bias  Determining causal direction  Is outcome due to peer effect or preexisting characteristics?  Self-selection bias  Determining causal direction  Is outcome due to peer effect or preexisting characteristics?

3. Overcoming Self-Selection  Using randomly generated roommate sample at Dartmouth College  Scardote proved this by regressing various background characteristics and proving no correlation among roommates  Using randomly generated roommate sample at Dartmouth College  Scardote proved this by regressing various background characteristics and proving no correlation among roommates

4. Dummy Variables  Used to distinguish outcomes based on subject background from outcomes generated by a peer effect  Pre-treatment groups around academic index (high school grades): top 25%, middle 50% or bottom 25%  Used to distinguish outcomes based on subject background from outcomes generated by a peer effect  Pre-treatment groups around academic index (high school grades): top 25%, middle 50% or bottom 25%

5. Multiple Regression  Used to verify causal direction of peer effect  Regression 1: subject GPA-roommate GPA  Regression 2: subject GPA-roommate background  Outcome variable (GPA) is determined by subject background, roommate background and roommate GPA.  Used to verify causal direction of peer effect  Regression 1: subject GPA-roommate GPA  Regression 2: subject GPA-roommate background  Outcome variable (GPA) is determined by subject background, roommate background and roommate GPA.

6. Conclusions  Why this happens  Choice architecture  Nurture over Nature?  Policy Implications  Education policy Questions?  Why this happens  Choice architecture  Nurture over Nature?  Policy Implications  Education policy Questions?