Much of today's software relies on programming code shared openly online. Yet, it is unclear why volunteer developers contribute to open-source software (OSS), a public good. We study OSS contributions of some 22,900 developers worldwide on the largest online code repository platform, GitHub,...

In the Solidarity Game (Selten and Ockenfels, 1998), two "rich" persons can support a "poor" one. A strong positive correlation between one rich person's solidarity contribution and his expected contribution of the other is observed. This paper investigates the causality behind this correlation....

Models to the issue of altruism which rely on externalities of well-being are rarely used explicitly. In this paper we compare such utility-based approaches with the standard approach on altruism which is based on externalities of income. Testable differences of both types of models are derived...

If a previously unpaid activity (donating blood) is paid then we often observe that this activity is reduced. In this paper, it is hypothesised that the price offered is taken as a proxy for the "market value" of the activity. Depending on how the actor valued the activity previously,...

How can a principal (an agent) ensure that an agent (a principal) will work (pay up), if payment (work) precedes work (payment)? When a banknote is torn in two, each part is by itself worthless. A principal can pre-commit to payment-on-delivery, by tearing a banknote and giving the agent the...

If a product has two dimensions of quality, one observable and one not, a firm can use observable quality as a signal of unobservable quality. The correlation between consumers' valuation of high quality in each dimension is a key determinant of the feasibility of such signaling. A firm may use...

Most incomes underlie some risk, i.e. ex ante they can be regarded as a lottery ticket. In every society, the lucky winners of this lottery compensate unlucky losers (unemployed workers or bankrupt entrepreneurs) privately and/or by public insurances. Do voluntary solidarity payments depend on...

In mainstream economics individuals are supposed to be driven only by their self-interest. By contrast, surveys clearly show that people do care about fairness in their demand for redistribution. In this article, in the spirit of the new synthesis in moral psychology (Haidt, 2007: The new...

Is there a way of matching donations that avoids crowding out? We introduce a novel matching method where the matched amount is allocated to a different project, present some simple theoretical considerations that predict reduced crowding out or crowding in (depending on the degree of...

This paper experimentally investigates trust and trustworthiness in a repeated and sequential three-player trust game with probabilistic returns and information asymmetry. It adds to the existing literature by combining experimental features from recent work in the trust game. The authors use...