Two event-study plots of estimated CWA effects on water quality (in Panel A) and population (in Panel B) by year. Panel A plots changes in dissolved oxygen levels (mg/L) over time from 1963 through 1992, showing little change prior to 1972 and steady, positive increases afterward, with most post-1972 estimates statistically above zero. Panel B plots changes in log population by decade from 1930 through 2000, showing flat or negative coefficients before 1970 and modest positive, statistically significant increases after 1970. Both panels include 95% confidence intervals around point estimates and a vertical dashed red line marking the CWA’s passage in 1972.
💧 Clean water mandates are costly, but they can drive local growth! 🏘️
A new #JAERE study finds that the 1972 Clean Water Act tripled resident user fees 💸 — yet surface water quality improved 19% and populations grew 13–30% faster in municipalities under 10,000 people.
📈 #JaereFigureFriday
📉 #Econsky