The message of this presentation is: by taking into account heterogeneity of the population in modelling macroeconomic behavioral relations one can make use of cross-section data in addition to aggregate time series data. To rely on this richer data set - i.e., time series of cross-section data - will improve the empirical content of macro-modelling.
Hildenbrand, W., & Kneip, A. (2000). [On aggregation of micro-relations - a research program]. Revue économique / Ecole des hautes études en sciences sociales, 51(3), 435-443. https://hdl.handle.net/2078.5/142827 (Original work published 2000)