Dynamic effects of enforcement on cooperation.

In situations where social payoffs are not aligned with private incentives, enforcement with fines can be a way to sustain cooperation. In this paper we show, by the means of a laboratory experiment, that past fines can have an effect on current behavior even when no longer in force. We document two mechanisms: (i) Past fines affect directly individuals' future propensity to cooperate, and (ii) when fines for noncooperation are in place in the past, individuals experience higher levels of cooperation from partners and, consistent with indirect reciprocity motives, are in turn nicer toward others once these fines have been removed. This second mechanism is empirically prevalent and, in contrast with the first one, induces a snowball effect of past enforcement. Our results can inform the design of costly enforcement policies.

How laws affect the perception of norms: Empirical evidence from the lockdown.

Laws not only affect behavior due to changes in material payoffs, but they may also change the perception individuals have of social norms, either by shifting them directly or by providing information on these norms. Using detailed daily survey data and exploiting the introduction of lockdown measures in the UK in the context of the COVID-19 health crisis, we provide causal evidence that the law drastically changed the perception of the norms regarding social distancing behaviors. We show that this effect of laws on perceived norms is mostly driven by an informational channel and that the intervention made perceptions of social norms converge to the actual prevalent norm.

Tako-tsubo: a transitory impairment of microcirculation? A case report.

The tako-tsubo syndrome, or transient left ventricular apical ballooning, has been widely described in Japan as a cardiomyopathy which resembles acute myocardial infarction on presentation, but characterized by a normal coronary tree and a favorable outcome. Conversely few series have been described in Europe and etiology and mechanism are still unknown. We describe the case of a 74-year-old Italian woman with tako-tsubo cardiomyopathy, one of the first Italian cases reported to our knowledge. In the acute phase, echocardiography and ventriculography showed the typical mid-apical systolic left ventricular dysfunction, with an angiographically normal coronary tree. A few days after, technetium-99m single-photon emission computed tomography disclosed a large mid-apical perfusion defect and dobutamine stress echocardiography showed a typical "biphasic" response. Three months later, all of these tests normalized with normal left ventricular function. In conclusion, the results of functional tests, during the acute and subacute phases, suggest that, in the absence of evident coronary spasm, a transitory reduction of the coronary reserve played a role in the pathogenesis. In the absence of epicardial coronary obstruction this could be due to a transient microcircle dysfunction, and may be attributed to a spasm followed by impaired vasodilation capability.