Student Faculty Macro Lunch: “Reconciling Treatment Effects Estimates across Levels of Aggregation”

Event details Date: Tuesday, September 8, 2026 Time: 12:00 PM to 1:00 PM Location: Evans 597 Type: Student Life About this event Abstract: Empirical researchers often estimate treatment effects at different levels of aggregation to address confounding shocks or to detect violations of the stable unit treatment value assumption. Using eight widely used datasets on trade, employment, syndicated loans, patents, and stock holdings, we document that disaggregated data share common properties that complicate comparisons across aggregation levels. We show that, under standard specifications, these properties can lead treatment effect estimates to differ across levels of aggregation even in the absence of shocks or SUTVA violations. These gaps arise mechanically from implicit weighting across levels of aggregation, entry and exit, and Jensen’s inequality. We characterize the conditions under which they become quantitatively important and propose simple approaches that are not sensitive to these sources of bias. Using practical examples, we show how aligning estimates across levels of aggregation can help researchers separately identify confounding shocks, spillovers, and extensive-margin changes at little additional cost. Official event details: https://events.berkeley.edu/econ/event/326722-student-faculty-macro-lunch-reconciling-treatment