No reason to expect large and consistent effects of nudge interventions | PNAS

"Nudge interventions may work, under certain conditions, but their effectiveness can vary to a great degree, and the conditions under which they work are barely identified in the literature....

We argue that, as a scientific field, instead of focusing on average effects, we need to understand when and where some nudges have huge positive effects and why others are not able to repeat those successes (2, 4, 5). Until then, with a few exceptions [e.g., defaults (6)], we see no reason to expect large and consistent effects when designing nudge experiments or running interventions."