Kimberley Scharf, Sarah Smith, 16 September 2016

The rise of peer to peer (P2P) fundraising – soliciting donations on behalf of a charity for undertaking an activity  – has paralleled the growth of online social networks, but the incentives driving online donation behaviour are still poorly understood. This column examines giving behaviour for a large sample of P2P fundraising projects that individuals promoted to their Facebook friends. A negative relationship is found between the number of friends and donation size. The findings suggest a ‘relational altruism’ motive, where donors give because they care about the person who is raising the money.

Michal Bauer, Christopher Blattman, Julie Chytilová, Joseph Henrich, Edward Miguel, Tamar Mitts, 02 July 2016

The past decade has seen rapid growth in an interdisciplinary body of research examining the legacy of war on social and political behaviour. This column presents a meta-analysis and synthesis of this research. Evidence from surveys and experiments from over 40 countries reveals a stylised fact: individual exposure to war-related violence tends to increase social cooperation, community participation, and pro-social behaviour. However, these changes are mainly directed towards people from the same community.

Lars Ivar Oppedal Berge, Kjetil Bjorvatn, Simon Galle, Edward Miguel, Daniel Posner, Bertil Tungodden, Kelly Zhang, 11 February 2016

Ethnic divisions have been shown to adversely affect economic performance and political stability, particularly in Africa. However, the underlying mechanisms remain poorly understood. Using experimental data from Kenya, this column studies whether one potential mechanism – co-ethnic bias – affects altruism. Strikingly, most tests yield no evidence of co-ethnic bias, suggesting that other mechanisms must be driving the negative association between ethnic diversity and economic and political outcomes in Africa.

James Andreoni, Justin M Rao, 16 December 2010

At a time when many people are asking themselves what to give their friends and family for Christmas, this column asks why we bother to give anything at all. In the economic laboratory, subjects exhibit significant levels of altruistic giving and aversion to unfairness. Outside the laboratory however, we encounter vast amounts of poverty and inequality and yet only give a tiny fraction of our income to charity.

Nicola Lacetera, Mario Macis, 04 November 2008

Episodes of blood supply shortage are the norm rather than the exception. “Pure” altruism is apparently not enough to guarantee a steady supply of blood, but economic incentives to donate might crowd-out intrinsic motivations. This column presents evidence that blood donors respond to material incentives and public recognition in the way predicted by standard economic theory. Rewarding them could increase blood supply.