Delad nota, ökat matintag

Ogillar du, liksom jag, att dela notan på restaurang? Då bör du finna resultaten i studien ”The Inefficiency of Splitting the Bill”, publicerad i The Economic Journal, av intresse. När tre versioner av ett experiment på restaurang genomfördes — ett där alla betalar individuellt, ett där notan delas lika och ett där någon annan betalar hela notan — blev utfallet det följande:

Med andra ord:

We find that the theoretical predictions work: people react to changes in incentives and they largely seem to ignore negative externalities. These results have great importance in the design of institutions. Institutions and rules that ignore the effect of negative externalities are inefficient – not only in theory, but also in practice. This inefficiency is the result of people playing the equilibrium of the game; even if they all prefer to be in a ‘different game’ (e.g., pay the bill individually). Interestingly, when asked which mechanism they would prefer, prior to informing them which mechanism they would face, 19 (80%) out of the 24 subjects we asked indicated they would prefer the individual pay over splitting the bill. However, when forced to play according to the less preferred set of rules (splitting the bill), subjects nevertheless minimise their losses by taking advantage of others.

Människor är, som det verkar, i rätt hög grad själviska. En intressant fråga som tas upp i avslutningen av artikeln är varför människor går med på att dela notan. Vad tror du?