  Nudging is a burgeoning topic in science and in policy, but evidence on the
effectiveness of nudges among differentially-incentivized groups is lacking.
This paper exploits regional variations in the roll-out of the Covid-19 vaccine
in Sweden to examine the effect of a nudge on groups whose intrinsic incentives
are different: 16-17-year-olds, for whom Covid-19 is not dangerous, and
50-59-year-olds, who face a substantial risk of death or severe dis-ease. We
find a significantly stronger response in the younger group, consistent with
the theory that nudges are more effective for choices that are not meaningful
to the individual.
