Effort and comparison income

"This paper considers the effect of status or relative income on work effort combining experimental evidence from a gift-exchange game with ISSP survey data. We find a consistent negative effect of others' incomes on individual effort in both datasets. The individual's rank in the income distribution is a stronger determinant of effort than others' average income, suggesting that comparisons are more ordinal than cardinal. We then show that effort is also affected by comparisons over time: those who received higher income offers or had higher income rank in the past exert lower levels of effort for a given current income and rank"--Forschungsinstitut zur Zukunft der Arbeit web site.