Business Cycles
Disaggregation

A business cycle downturn implies that the level of activity of the aggregate economy has fallen. In discussing economic fluctuations, fine details are properly glossed over and abstracted away. Such minutiae are trivial in relation to the fluctuations in a five-trillion dollar economy. But where should the line between detail and relevance be drawn? In Discussion Paper No. 1236, Research Fellow Danny Quah examines how a single picture of aggregate GNP fluctuations can help to understand the diversity in disaggregated, but large and significant sectors of the economy. He develops a simple model and econometric tools for analysing the joint behaviour of aggregate and disaggregate fluctuations.

There are, of course, many different kinds of disaggregates to study. This paper focuses on US regional, that is, geographically distinct, fluctuations; documenting their diverse experiences over aggregate economic fluctuations. The analysis leads to a picture of US business cycles as a spatial `wave' of regional activity, fluctuating over time but with well-defined regular features.

Aggregate and Regional Disaggregate Fluctuations
Danny T Quah

Discussion Paper No. 1236, September 1995 (IM)