This paper studies how online dating platforms have impacted marital outcomes, assortative matching, and sexually transmitted disease (STD) rates in the United States. We construct county-level measures of online dating usage using data from website-based platforms (2002-2013) and mobile app-based platforms (2017-2023). Leveraging county-level variation and an instrumental variable strategy, we show in the desktop era, a 1% increase in online dating sessions raises divorce rates by 0.50%, while in the mobile era, a 1% increase in online dating activity lowers marriage and divorce rates by 0.40% and 0.33%, respectively. We also document shifts in assortative matching. Desktop sites reduce sorting along education and employment dimensions, whereas mobile sites reduce sorting by employment, but increase sorting by race. Across both eras, we find no evidence that greater online dating usage increases average STD rates. Average effects are negative or statistically insignificant, but are positive for some subpopulations. We develop a search and matching model where technological changes impact search costs, market size, and market noise can explain our empirical findings.

That is from a new paper by Daniel Ershov, Jessica Fong, and Pinar Yildirim.  Via the excellent Kevin Lewis.