The Impact of the WWI Agricultural Boom and Bust on Female Opportunity Cost and Fertility

Using variation in crop prices induced by large swings in demand World War I, we examine the fertility response to increases in crop revenues during the period 1910-1930. Our estimates from samples utilizing both complete count decennial census microdata and newly collected county-level data from state health reports indicate that a doubling of the agricultural price index reduced fertility by around 8 percent both immediately and in the years following the boom. We further document that this effect was more pronounced in more agrarian areas and where the labor intensity of agriculture was more intense. Extensive robustness checks and analysis of potential mechanisms indicate that the decrease in fertility was driven by increased female opportunity costs which dominated any household income effects resulting from the price boom.