A research study has suggested that changes in hours worked over time are due, in part, to changes in tax rates.

A research study has suggested that changes in hours worked over time are due, in part, to changes in tax rates. “If taxes and (government expenditures) are high, that may lead to less work,” said one of the researchers. Supporting this theory since 2001, workers in the U.S. have increased their hours worked while tax rates have dropped. What theory or theories of motivation might explain such a change?