According to the Institute of Fiscal Studies gender wage differentials remain substantial and are a hot topic in policy debate. Inequalities between men and women are clearly of direct interest in their own right. In addition, poverty is increasingly a problem of low pay rather than lack of employment. The proportion of people in paid work is at a record high, and female employment has risen especially quickly, particularly among lone parents. Two-thirds of children in poverty now live in a household with someone in paid work. In an age when the main challenge with respect to poverty alleviation is to boost incomes for those in work, and when so many more women are in work than in the past, understanding the gender wage gap is all the more important.