In the vast majority of laboratory experiments documenting the existence of reciprocity subjects are endowed with windfall funds. In many environments with salient fairness considerations such endowments are known to inflate subjects’ other-regarding behavior, thereby creating a so-called...

In the vast majority of experiments documenting the existence of reciprocity subjects are endowed with windfall funds. In some situations such endowments might create a so-called “house money effect”. We identify two reasons why the source of endowment might matter for negative reciprocity:...