Post #3346643

Is the iPhone Birth Control? Causal Evidence from AT&T’s 2007–2011 Carrier Monopoly https://www.nber.org/papers/w35310 Backround: From the launch 2007 through Feb 2011, the iPhone was limited to AT&T subscribers in the US. Smarphone exposure was limited to AT&T’s cellular network making natural experiment possible Treated counties are systematically more urban than controls. They address this imbalance through the SDID estimator’s pre-treatment reweighting of controls and using a complementary entropy-balanced Poisson specification. ... Entropy-balanced Poisson and synthetic difference-in-differences event studies imply that access to the iPhone reduced births by 4.5–8.0% at ages 15–19 and 3.2–6.6% at ages 20–24, with statistically significant but smaller declines among older cohorts. Placebo analyses applied to Verizon and Sprint’s pre-2011 coverage footprint are null. .... National-survey evidence on time use and sexual behavior is consistent with the iPhone reducing in-person interactions, increasing pornography use, and reducing sexual frequency. #economics #demographics #socialMedia #socialScience