This study examines the gender-identity hypothesis in the context of the work hours and life satisfaction of highly educated wives based on the prototype model in identity economics, using the survey concerning social life and time budget 2007 by the JTUC Research Institute for Advancement of Living Standards (RENGO-RIALS), Japan. The empirical analyses showed that, frst, the gender-identity hypothesis was supported only for wives with  hildren. Second, with or without children, wives’ life satisfaction declined sharply when they worked for more than 20 h. 
 These fndings suggest that gender identity was an important factor for Japanese wives with children when they were choosing their number of work hours outside the home and underlined the Japanese social behavioral norm that “wives with children should not work.” This research contributes to the study of the Homo economicus’s nonrational economic behaviors, thus deepening analysis of the relationship between gender identity and working time; furthermore, it better explains why women undersupply labor in the market despite being highly educated.