Does voting history matter : analysing persistence in turnout

Individuals who vote in one election are also more likely to vote in the next. Modelling the causal relationship between consecutive voting decisions however is intrinsically difficult, as this positive association can exist due to unobserved heterogeneity (i.e. some fixed, but unobserved, characteristics makes voters consistently turn out to vote) or habit formation (i.e. past turnout decisions influence subsequent turnout decisions). This paper overcomes this problem using longitudinal data from the British National Child Development Study (NCDS) to examine voting behaviour across three elections. Utilising techniques developed in the econometrics literature we find that failing to control for unobserved heterogeneity overestimates the extent of habit formation by almost 100%. Estimating a dynamic model of voter turnout, allowing for unobserved heterogeneity, implies that voting in one election increases the probability of voting in the next by about 13%. This figure is far less than previous studies have identified.