Did the 1988 California tobacco law cut cigarette sales, and did it also affect neighboring states such as Nevada? This Python tutorial builds a look-alike California from other states in three steps, the last one letting nearby states be affected too, and finds that the drop in California holds up. It comes with an interactive app that runs in your web browser.
Which European regions actually influence each other? Instead of assuming that only bordering regions matter, we let growth data for 90 European regions from 2001 to 2019 reveal who the real neighbors are. This R tutorial comes with an interactive app that runs in your web browser.
Did a policy really work if it also affected the comparison regions? scspill, a Python package, estimates both the true effect and the spillover to them.
Are poorer regions catching up, and is inequality falling? geometrics answers with spatial methods in Python, Plotly figures, and no-code Streamlit apps.
Do industrial parks bring more economic activity to nearby towns, and who benefits? This Python tutorial compares places that got a park with places that did not, before and after it opened, using simulated data modeled on Ethiopia, and also looks at household welfare and outcomes for women. It comes with an interactive app that runs in your web browser.
How did the 2004 tsunami affect the economy of Aceh, Indonesia, over the long run? This beginner-friendly Python tutorial uses simulated data, nighttime lights, and several causal methods to compare damaged and undamaged areas before and after the disaster.
What happens to nearby home prices when a registered sex offender moves into a neighborhood? We compare homes close to the address with homes a little farther away, before and after the move, and show how the distance chosen as the cutoff can change the answer. This R tutorial comes with an interactive app that runs in your web browser.
How much did the 1988 California tobacco tax reduce cigarette sales? We build a look-alike California from other states and also measure how the policy spilled over to neighboring states such as Nevada, where people cross the border to buy cigarettes. This R tutorial comes with an interactive app that runs in your web browser.
When we measure how a relationship changes from place to place, hidden features of each place can distort the answer. This Python tutorial follows a 2026 study by Li and Fotheringham and uses simulated data on 225 places over three periods to show how following the same places over time removes that distortion. It comes with an interactive app that runs in your web browser.