usefully aggregated into a single sector model. Such an aggregation misleads the economist as to the economy's underlying …

This paper discusses the issue of consistent simple sum aggregation over assets within the context of expected utility … maximizing investors. The first part of the paper extends the Hicks and Leontief aggregation theorems of consumer choice theory … to the portfolio choice problem. Next, necessary and sufficient conditions for consistent simple sum aggregation are …

.S. manufacturing differ markedly even though response parameters are similar across industries. A similar aggregation effect is noted … estimation procedures. Observationally equivalent aggregation results can be generated by errors in variables models (see Aigner …

characteristics. A key decision for researchers in estimating this relationship is the level of aggregation, since the gravity … equation is log linear, whereas aggregation involves summing the level rather than the log level of trade flows. In this paper …

aggregate production functions by deriving their first- and second-order properties. Our aggregation formulas provide non … sufficient statistics. They allow us to generalize existing aggregation theorems and to derive new ones. We relate our results to …