Staggered Adoption Cohorts (Fixed Effects)

Using mm.dta, we want to evaluate the effect of improved chickpea adoption (icp) on yield. However, parcels adopt improved chickpeas at different times. We need to create a variable that stores the first time period a parcel ever had icp == 1.

• Sort the data by qnno and tindex.
• Create a variable first_icp that equals tindex if icp == 1, and missing otherwise.
• Use bysort qnno: to replace first_icp with the minimum value of first_icp for that parcel across all years (egen ... = min()).
• For parcels that never adopted improved chickpeas (missing(first_icp)), replace first_icp = 0.

You now have the exact cohort group variable needed for modern TWFE estimators. Run a TWFE regression using either xtreg with time dummies (i.tindex) or reghdfe and use eststo to save the result. What is the coefficient on improved chickpea adoption?

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