The use (and misuse) of statistics in understanding social mobility Seminar

Social mobility has emerged as one of the key academic and political topics in Britain over the last decade. Although economists and sociologists disagree on whether mobility has increased or decreased, and if this is a bigger issue in the UK than other developed countries, both groups recognise that education and skill plays a key role in explaining intergenerational persistence. This has led academics from various disciplines to investigate how rates of cognitive development may vary between children from rich and poor backgrounds.

A number of key studies in this area have reached one particularly striking (and concerning) conclusion that highly able children from disadvantaged homes are overtaken by their rich (but less able) peers before the age of 10 in terms of their cognitive skill. This has become a widely cited "fact" within the academic literature on social mobility and child development, and has had a major influence on public policy and political debate. In this paper, we show that this finding is due to a miss-interpretation of the data, and is largely a spurious statistical artefact caused by regression to the mean. As such, we break with conventional wisdom and the existing literature by suggesting that "bright" children from poor homes do not get overtaken by their rich but less able peers during the early school years.