Land Quality

We develop a new measure of land quality by estimating weights in a Poisson regression of grid-cell population on geographic characteristics and country fixed effects. Aggregating to countries, we construct average land quality (ALQ) and quality-adjusted population density (QAPD). We show: First, current income per capita is positively correlated with ALQ. Second, while income today is unrelated to conventional population density, it is strongly negatively related to QAPD. Third, this negative relationship was not present in 1820 and emerged because today’s lower income countries have experienced faster subsequent population growth. Fourth, countries with higher average land quality began sustained modern economic growth earlier, and this earlier takeoff largely explains the modern income-ALQ relationship. We posit a framework in which land quality induced denser populations in Malthusian equilibrium and, via agglomeration, earlier takeoffs. Less dense countries experienced larger population multipliers during their later demographic transitions due to imported health technologies.