In the utility function, consumption and leisure time might have interaction effects.
$$ U(C(L),L)$$
Currently, people’s overtime working hours increased. People hence spend more time on working and making money, and thus there is less time on leisure for people. Though wages are earned, people’s preference for less valuable goods is decreasing because of less time left on leisure. Meanwhile, consumption also takes time. Therefore, less leisure results in less consumption even though nominal income increase (did not consider the real terms now).
Ideas: Model(consumption is a function a leisure) + Empirical Analysis (include the interaction term)