On laws versus norms

I am more than a year late to this paper, but in fairness to me trolling economics journals isn't high on my list of priorities. 

Why does it seem to happen that people who live below I-10 have terrible recoveries from surgeries, while people who live above it do better? Why do some folks cheat and steal, while others don't? Is it norms, or is it laws? I suppose, and Daron Acemoglu and Matthew O. Jackson back me up, that it's both. But it's a particular sort of both: norms are strengthened when working in concert. If the two are divergent, too much, it'll lead to worse outcomes. Stronger laws can reduce good among the law-abiding and increase it among the law breakers; it is preferable to strengthen laws gradually for that reason:

We further show that laws that are in strong conflict with prevailing social norms may backfire and lead to a significant decline in law-abiding behavior in society. In contrast, gradual imposition of moderately tight laws can be effective in changing social norms and can thus alter behavior without leading to pervasive lawlessness.

Laws have to reflect norms, up to a point. It's interesting to consider when thinking about how to resolve unwanted outcomes that are still pervasive.