In Australia’s tax and social welfare system, many women face effective marginal tax rates (EMTRs) on work income which are higher than the marginal tax rates of the personal income tax structure. Even for some top income earners, high EMTRS may be produced. For example, if those caring for young children (mostly women) return to work or increase their work hours, this simultaneously requires them to pay increased taxes (and, possibly, the Medicare Levy) at the same time that family payments and child care subsidies are phased out. These high EMTRs tend to affect women more than men because women tend to be secondary earners in families either in terms of lower wages or lower working hours.