The twelfth seminar in the CLOSER Longitudinal Methodology Series featured talks from Vasiliki Bountziouka and Chris Belfield. Vasiliki is a Research Associate at the UCL Institute of Child Health and Chris is a Research Economist at the Institute for Fiscal Studies (IFS). Vasiliki presented an investigation of the distribution of childhood visual function in the UK and the associations with early life social position. Chris discussed how his project has worked on deriving harmonised measures of income which are consistent both within and across the CLOSER studies.
Dr Vasiliki Bountziouka
Trends in visual function in childhood: the emerging importance of gender and social position in visual health inequalities
Although country-specific strategic plans exist to tackle social inequalities in visual health in adults, underpinned by a growing evidence-base, little is known about trends in distribution of visual function in childhood and its association with social position. We present an investigation of the distribution of childhood visual function in the UK and associations with early life social position, over a quarter century of social change. We used harmonised data from the British 1946, 1958 and 1970 national birth cohorts and found evidence of a temporal decline in visual function in childhood with the risk of overall impaired vision increasing by 20% over this period. Social position at birth and in childhood was associated, in opposing directions, with this cohort effect with girls consistently at increased risk. We will discuss how the patterns of associations with social position varied by vision category and how early life social position may have contributed to the current known social patterning in visual function in older adults in the UK.
Deriving harmonised measures of income across and within studies
Many research questions of vital importance to public policy require consistent data on socio-economic status both within and across cohorts. However, across the waves and studies that make up the four major British Cohort Studies, information about income is recorded using a various different methods. The resulting measures are, therefore, inconsistent and this creates a barrier to reliable cross cohort analysis. In this work, we account for these differences and derive harmonised measures of income which are consistent both within and across studies. We use external data sources to validate these measures and test for Two Sample Two Stage Least Squares bias using simulated data. We use these consistent measures of income to explore the role of assortative mating and the tax and benefit system in perpetuating or mitigating intergenerational income persistence.