The Estimation Voyage — Guided Edition

This is the guided version of the Estimation Voyage. Complete each stage in order.
We want to estimate the causal effect of average weekly study hours on GPA for a panel of n = 10,000 students, each observed over T = 4 semesters. But study time may be driven by factors we can’t observe — in particular, persistent student ability a_i (students who are more able may study differently and earn higher GPAs) and time-varying hard-course shocks h_it (a hard semester may push a student to study more while directly lowering their GPA). The university assigns students to dormitory rooms at random; some dorms are closer to the library than others. Work through 6 stages: each stage introduces a new complication, and you must compute the slope estimates yourself before unlocking the next.