One reason why the empirical record isn't more full of nudges turning
into diktats is that government typically issues diktats from the
get-go. We Americans were commanded, without any prior "nudging," to
use low-flow faucets. We were commanded, without prior "nudging," not
to use marijuana. We were commanded, without prior "nudging," to set
aside a portion of our earnings into Social Security. Ditto, of course,
for countless other aspects of our lives - including being commanded by
Obamacare, without prior "nudging," to buy health insurance as designed
by government officials.
If the arrogant busybodies who itch to practice social engineering
are somehow persuaded to launch more of their engineering projects with
"nudges" rather than with diktats, any significant failure of those
"nudges" to produce the desired socially engineered outcomes will
inevitably be taken as proof that those "nudges" should be turned into
In short, the nanny state is a Tiger Mom: Do it voluntarily, or else.