The parameter ?dos captures any partial correlation between tuition rates and homeownership among the control group, absorbing any state-level shocks that affect both tuition and the homeownership rate. Note that in specifications with state-by-year fixed effects ?2 is not identified, as the average tuition rate is collinear with the fixed effects. The parameter ?3 captures the average difference in homeownership rates between the treatment and control groups. We are left identifying ?step step one, the effect of student loan debt on homeownership, by the widening or shrinking of the gap in homeownership rates between public 4-year school attendees and the general population as tuition rates change, analogous to a difference-in-differences estimator.
Estimates of ?1 may be inconsistent if membership in the treatment group is influenced by tuition rates. In particular, if the attendance decisions of students considering public 4-year universities are swayed by the prevailing tuition, then our estimates would suffer from sample selection bias. However, we will show that the variation in tuition exploited in this study exert no meaningful effect on the probability of a student attending a public 4-year university. Ler mais