Upstream reciprocity (also called generalized reciprocity) is a putative mechanism for cooperation in social dilemma situations with which players help others when they are helped by somebody else. It is a type of indirect reciprocity. Although upstream reciprocity is often observed in experiments, most theories suggest that it is operative only when players form short cycles such as triangles,...

The evolution of cooperation among nonrelatives has been explained by direct, indirect, and strong reciprocity. Animals should base the decision to help others on expected future help, which they may judge from past behavior of their partner. Although many examples of cooperative behavior exist in nature where reciprocity may be involved, experimental evidence for strategies predicted by direct...

The study of reciprocal altruism, or the exchange of goods and services between individuals, requires attention to both evolutionary explanations and proximate mechanisms. Evolutionary explanations have been debated at length, but far less is known about the proximate mechanisms of reciprocity. Our own research has focused on the immediate causes and contingencies underlying services such as fo...

It is well known that Frobenius reciprocity is one of the central tools in the representation theory. In this paper, we discuss Frobenius reciprocity in the theory of automorphic functions. This Frobenius reciprocity was discovered by Gel’fand, Fomin, and PiatetskiShapiro in the 1960s as the basis of their interpretation of the classical theory of automorphic functions in terms of the represent...

This article is devoted to the problem of the validity of the reciprocity theorem in high-temperature superconductors (HTSC). The violation of the reciprocity theorem in zero external magnetic fields has been studied. Experimental data obtained for two different superconducting materials: BiSrCaCuO and YBaCuO are presented. Results show that the basic form of the reciprocity theorem (without co...

We examine in detail the circumstances under which reciprocity, as defined in Bagwell and Staiger (1999), leads to fixed world prices. We show that a change of tariffs satisfying reciprocity does not necessarily imply constant world prices in a world of many goods and countries. While it is possible to find tariff reforms that are consistent with both reciprocity and constant world prices (as B...

In 1985, K. S. Williams, K. Hardy and C. Friesen [11] published a reciprocity formula that comprised all known rational quartic reciprocity laws. Their proof consisted in a long and complicated manipulation of Jacobi symbols and was subsequently simplified (and generalized) by R. Evans [3]. In this note we give a proof of their reciprocity law which is not only considerably shorter but also she...

We study the role of reciprocity in a labor market field experiment. In a recent paper, Gneezy and List (2006) investigate the impact of gift exchange in this context and find that it has only a transient effect on long run outcomes. Extending their work to examine both positive and negative reciprocity, we find consonant evidence in the positive reciprocity condition: the gift does not work we...

The present study examines both positive and negative norms of reciprocity in managerial work relationships by assessing three components of reciprocal behavior: immediacy, equivalence, and interest motive. The findings show that subordinate reports of immediacy, equivalence, and self-interest were negatively associated, and mutual-interest was positively associated, with relationship quality a...

This paper analyses efficient contracts for digital content, focusing on the music industry. It contributes to the quest for an efficient intellectual property rights environment for information goods. Moreover, it adds an interesting application to the field of behavioural economics. The model is set in a contract theory framework with the copyright holder being the principal and a consumer th...