Can governments increase private savings by taxing savings up front instead of in retirement? Roth 401(k) contributions are not tax-deductible in the contribution year, but withdrawals in retirement are untaxed. The more common before-tax 401(k) contribution is tax-deductible in the contribution...

Many Americans fail to get life-saving vaccines each year, and the availability of a vaccine for COVID-19 makes the challenge of encouraging vaccination more urgent than ever. We present a large field experiment (N=47,306) testing 19 nudges delivered to patients via text message and designed to...

Medium- and long-run dynamics undermine the effect of automatic enrollment and default savings-rate auto-escalation on retirement savings. Our analysis of nine 401(k) plans incorporates the facts that employees frequently leave firms (often before matching contributions from their employer have...

Can governments increase private savings by taxing savings up front instead of in retirement? Roth 401(k) contributions are not tax-deductible in the contribution year, but withdrawals in retirement are untaxed. The more common before-tax 401(k) contribution is tax-deductible in the contribution...

We present a pre-registered experiment testing the effects of three, high-payoff (up to $50,000) vaccine regret lotteries in Philadelphia. In each drawing, residents of a randomly selected “treatment” zip code received half of the 12 lottery prizes (boosting their chances to 59-98x those of...