It is shown how one can effectively use microdata in modelling the change over time in an aggregate (e.g. mean consumption expenditure) of a large and heterogeneous population. The starting point of our aggregation analysis is a specification of explanatory variables on the micro-level....

Engel's verbal formulation of his Law expresses a "negativ stochastic association" of the bivariate distribution of income and food share across the population. Among the many different definitions of association four are chosen: Kendall's tau, negative quadrant dependence, stochastically...

This paper deals with different concepts of income elasticities of demand for a heterogenous population and the relationship between individual and aggregate elasticities is analyzed. In general, the aggregate elasticity is not equal to the mean of individual elasticities. The difference depends...