externalities, treatment of one unit often affects other units. To explore the implications of applying standard quasi …

goods provision embedded in a social context and find that in the absence of explicit norms externalities have almost no … effect. With an endogenously formed provision norm positive as well as negative externalities dampen provision as compared to … no externalities. We explain the surprisingly low provision under positive externalities by the providers' increased risk …

, theory even predicts that strategic interaction forces firms to set the market clearing price. For society, this would be …

cost and risk. Nonetheless standard theory predicts too little innovation. Arguably the problem is exacerbated by … appropriation than predicted by standard theory. But the risk and the experience of appropriation does not deter innovation. We find … even more innovation than predicted by theory, and actually more than would be efficient. In the lab, the prospect of …