Consistent aggregation of production data across commodities and states was tested using Lewbel's generalized composite … commodity theorem (GCCT). This was the first empirical GCCT test for consistent geographic aggregation and was applied to two … groups of states. Consistent commodity aggregation was tested in all states for two output groups and three input groups and …

-agriculture. Standard aggregation procedures ignore the variability within sectors, and underweight the importance of highly protected … that using optimal aggregation procedures increases the measured importance of agricultural trade reform relative to non …

separability conditions for aggregation have been rejected is reconsidered to determine if aggregation can be based on the GCCT … of formulating aggregates prior to conducting tests for aggregation is addressed. …

The generalized composite commodity theorem (Lewbel 1996) is used to test for consistent aggregation of U.S. and … aggregated into as few as five categories. The aggregation of all outputs into a single output cannot be supported in either …