How much does war lower the living standards of a country? Using data on 160 countries from 1955 to 2015 in Stata, we follow each country over time to separate the damage of war from lasting national differences, and find that about half of the long-run cost works through weaker institutions. The tutorial includes an interactive app that runs in your web browser.
Did an after-school tutoring program really raise student grades, or were grades rising everywhere? This Python tutorial compares 10 tutored high schools with 25 others, before and after the program, to separate its effect from the general upward trend. It comes with an interactive app that runs in your web browser.
As countries grow richer, do the gaps between their regions first widen and then narrow, or do they widen again at the top? This Python tutorial uses satellite images of night lights for about 180 countries and compares each country with itself over time, finding an N-shaped pattern. It comes with an interactive app that runs in your web browser.
Does an economic downturn make civil conflict more likely? Using yearly data on more than 5,000 African regions in Stata, we treat rainfall shocks as a natural experiment for local economic activity, measured by night lights seen from space, and find that economic decline raises the risk of conflict. It comes with an interactive app that runs in your web browser.
Did an after-school tutoring program raise the grades of low-income high school students? Using simulated data on 35 schools in Stata, we compare how grades changed in schools with and without the program, and we check whether both groups were on similar paths before it started. It comes with an interactive app that runs in your web browser.
Do all countries respond the same way to democracy or inflation? In Stata, we use a method that sorts countries into hidden groups that behave alike, and find that the average link between democracy and economic growth hides a strong positive effect in 57 countries and a negative one in 41. It comes with an interactive app that runs in your web browser.
What does a regression that adjusts for country and year differences actually do to the data? Using simulated data for 150 countries in R, we show step by step that it equals subtracting country and year averages before a simple regression, and why the usual margins of error then need a fix. It comes with an interactive app that runs in your web browser.
How sure can we be about an estimate when the same firms are observed year after year? Using simulated data for 100 firms in Python, we compare several ways of measuring the margin of error and show that no margin of error can fix an estimate that is biased to begin with. It includes an interactive app that runs in your web browser.
Which factors truly drive economic growth, such as investment, education or trade? Using 73 countries over four decades, we average across every possible combination of factors instead of betting on a single model, while allowing growth itself to shape those factors. This R tutorial comes with an interactive app that runs in your web browser.
When a state raises cigarette prices, do smokers simply buy in the state next door? Using cigarette demand in 46 American states from 1963 to 1992, we measure how prices and income affect smoking at home and in neighboring states, and how habits carry over from year to year. This R tutorial comes with an interactive app that runs in your web browser.