One person's trash is another person's treasure: In search of an efficient property regime for waste in the Global South.

Previous literature has studied waste picking as an economic, social, and environmental phenomenon of great importance in the Global South. The legal foundations of waste picking have, however, received little scholarly attention. Surveys conducted by the global network Women in Informal Employment: Globalizing and Organizing show that laws about access to waste are a central concern for many waste pickers. We study the efficiency of different property regimes for waste in the Global South. The candidate regimes are exclusionary ownership of waste by one category (private companies or the waste pickers), public ownership by the state, common or communal ownership, and res nullius ("first in time, first in right"). Any property regime that tries to exclude the waste pickers from accessing waste is associated with high transaction costs. We argue that the res nullius regime, complemented by waste pickers' organizations, regulates the waste sector efficiently in the Global South.

Testosterone and Cortisol Jointly Predict the Ambiguity Premium in an Ellsberg-Urns Experiment.

Previous literature has tried to establish whether and how steroid hormones are related to economic risk-taking. In this study, we investigate the relationship between testosterone (T) and cortisol (C) on one side and attitudes toward risk and ambiguity on the other. We asked 78 male undergraduate students to complete several tasks and provide two saliva samples. In the task "Reveal the Bag," participants expressed their beliefs on an ambiguous situation in an incentivized framework. In the task "Ellsberg Bags," we elicited from the participants through an incentive-compatible mechanism the reservation prices for a risky bet and an ambiguous bet. We used the difference between the two prices to calculate each participant's ambiguity premium. We found that participants' salivary T and C levels jointly predicted the ambiguity premium. Participants featuring comparatively lower levels of T and C showed the highest levels of ambiguity aversion. The beliefs expressed by a subset of participants in the "Reveal the Bag" task rationalize (in a revealed preference sense) their choices in the "Ellsberg Bags" task.