Payments and discounts incentivize participation in many transactions about which people know little, but can learn more --- payments for medical trial participation, signing bonuses for job applicants, or price rebates on consumer durables. Who opts into the transaction when given such...

We study experimentally when, why, and how people intervene in others' choices. Choice Architects (CAs) construct opportunity sets containing bundles of time-indexed payments for Choosers. CAs frequently prevent impatient choices despite opportunities to provide advice, believing Choosers...