Our paper introduces a new estimation method for arbitrary temporal heterogeneity in panel data models. The paper provides a semiparametric method for estimating general patterns of cross-sectional specific time trends. The methods proposed in the paper are related to principal component...

It is shown how one can effectively use cross-section data in modelling the change over time in aggregate consumption expenditure of a heterogeneous population. The starting point of our aggregation analysis is a dynamic behavioral relation on the household level. Based on certain hypotheses on...