This working paper considers how hours of work and labour force participation are likely to respond to tax reforms. As regards hours of work, the analysis looks at married women and lone parents. Married women constitute a group which responds to incentives, as shown by experimental and sample survey studies. Lone parents, an important fraction of the working age population in some countries, often are subject to special tax and income support provisions and have limited sources of alternative income. A second part of the analysis concerns inflows to and outflows from employment, labour force participation and duration of unemployment as they affect men and women in different age groups and with differing family responsibilities. The analysis is based mainly on the well-documented tax reforms in the United Kingdom. The first part of the paper develops the appropriate methodology for analysing labour supply responses to tax changes and the second part attempts to clarify the magnitude ...