Mike Brewer

Job Changes and Hours Changes: Understanding the Path of Labor Supply Adjustment

We use British panel data to investigate single women’s labor supply changes in response to three reforms that affected individuals’ work incentives. We use these reforms to identify changes in labor supply. There is evidence of small hours of work effects for two of such reforms. A third reform in 1999 instead led to a significant increase in single mothers’ hours of work. The mechanism by which the labor supply adjustments were made occurred largely through job changes rather than hours changes with the same employer. This is little overall effect of the reforms on wages.

Inference with Difference-in-Differences Revisited

Abstract A growing literature on inference in difference-in-differences (DiD) designs has been pessimistic about obtaining hypothesis tests of the correct size, particularly with few groups. We provide Monte Carlo evidence for four points: (i) it is possible to obtain tests of the correct size even with few groups, and in many settings very straightforward methods will achieve this; (ii) the main problem in DiD designs with grouped errors is instead low power to detect real effects; (iii) feasible GLS estimation combined with robust inference can increase power considerably whilst maintaining correct test size – again, even with few groups, and (iv) using OLS with robust inference can lead to a perverse relationship between power and panel length.

What Really Happened to Child Poverty in the UK under Labour's First Term?

Child poverty in Britain fell in Labours first term, though by much less than micro-simulation exercises suggested. Nonetheless, the decline is statistically significant, and is greater if measured just in the last 6 months of 2000/1, rather than the whole year. The decline also proves robust to the choice of poverty line, although that which the Government has emphasised (60% of contemporary income) shows a somewhat bigger drop than any other than any other poverty line that is a fraction of median income. Among those who remain poor, the average shortfall in measured income below the poverty line has increased since 1996/7. Looking ahead, the methodology currently used in official poverty statistics may limit the potential to reduce child poverty significantly further. Copyright 2003 Royal Economic Society.

Accounting for Changes in Income Inequality: Decomposition Analyses for the UK, 1978–2008

We analyse income inequality in the UK from 1978 to 2009 in order to understand why income inequality rose very rapidly from 1978 to 1991 but then remained broadly unchanged. We find that inequality in earnings among employees has risen fairly steadily since 1978, but other factors that caused income inequality to rise before 1991 have since gone into reverse. Inequality in investment and pension income has fallen since 1991, as has inequality between those with and without employment. Furthermore, certain household types – notably the elderly and those with young children – which had relatively low incomes in the period to 1991 have seen their incomes converge with others.

Why Did Britain's Households Get Richer? Decomposing UK Household Income Growth between 1968 and 2008-09

 Average real UK household income has almost doubled over the past forty years. With four decades of micro-data on household incomes, and relatively simple decomposition methods, we document the contribution to this growth in the mean net household income of working-age households from different income sources, and break down further changes in employment income by household member and into separate participation, hours and hourly wage effects. We also perform such analyses for the mean income of the richest working-age households, and among a group defined by having a low household income but a strong connection to the labour market.

How taxes and welfare distort work incentives: static, lifecycle and dynamic perspectives

Personal taxes and benefits affect the incentive to work over the lifecycle by altering income-age profiles, insuring against adverse shocks, and changing the returns to human capital. Previous work investigating the impact of taxes and benefits on work incentives has tended to ignore these dynamic considerations. In this paper, we use a dynamic model to show how a lifecycle perspective alters our impression of the effect of the tax and benefit system on female work incentives. We describe how work incentives change over the life and show how they depend on lifecycle circumstances. We also devise a forward-looking measure of work incentives that incorporates all the dynamic considerations likely to affect work decisions at any given age. We find that individuals experience considerable variability in work incentives across life that outweighs the variability across individuals. Changes pattern of family types across life is key to explaining these patterns: work incentives vary dramatically depending on family composition, and most women experience a number of different family types during the course of their lives. We also find that differences in family type are an important explanation for why static and forwardlooking PTRs diverge, though this is more to do with differences in how women in families with different compositions behave.

The distributional effect of the 2008 Pre-Budget Report

The Pre-Budget Report given by the Chancellor on 24th November 2008 contained a number of changes to the tax and benefit system to come into effect at various points over the next three years. This briefing note expands on the information provided at a briefing given by IFS researchers on the day after the Pre-Budget Report1. It gives details of the changes to taxes, benefits and tax credits directly affecting households, and the total distributional impact of measures announced in PBR 2008 together with pre-announced changes, by income and expenditure decile and household type, at three points in time – January 2009, April 2009 and April 2011. It also discusses what PBR 2008 does to our impression of all tax and benefit changes under this Government. Finally, it discusses what PBR 08 did for child poverty in 2010/11 and the likely effects of the income tax changes for those earning more than £100,000 a year.