Household income and sticky floors in children’s cognitive development: Evidence from the United Kingdom Millennium Cohort Study
While there is a rich literature on the socio-economic gaps in children’s average cognitive test scores in the United Kingdom, there is less evidence on the differences in children’s transitions along the ability distribution. Using data from five sweeps of the UK Millennium Cohort Study at the ages of 9 months, 3 years, 5 years, 7 years and 11 years, this paper analyses the role of household income, relative to other socio-economic factors, in influencing children’s chances of moving up or down the age-specific cognitive ability distribution as they grow older. Descriptive findings indicate a high level of variability between ages 3 and 11, but children from income-poor households are more likely to get trapped in the bottom of the age-specific cognitive ability distribution. Event history analysis shows that household income protects children from falling into the lowest-performing group without necessarily helping existing low performers improve. In contrast, parental education both protects children from slipping into low performance and helps them move up if they fall into it. While this is, perhaps, disheartening because household income is more amenable to policy than parental education, there is potential for income-enhancing policies to protect children from scoring poorly in the first place.