Aggregation and the Factoral Content of Trade

The composition of the human capital stock and its relation to international trade: Evidence from the US and Britain

“…Indeed, Brecher and Choudri (1982) have argued that unwarranted disaggregation can invalidate the factor content model. On the other hand excessive agggregation can also not be valid (Gift and Marxsen, 1984) and can lead to important patterns of specialisation being ignored. Accordingly, care was taken to select specific categories that plausibly represented skills with two characteristics.…”

Estimating the HOV Model with Technology Differences Using Disaggregated Labor Skills for the United States and the United Kingdom

“…8. Gift and Marxsen (1984) point out that excessive aggregation is also invalid if it ignores important patterns of specialization. 9.…”

The Skill and Higher Educational Content of Uk Net Exports

“…However, such an approach has a drawback as some aggregation of certain factors (skills and different types of physical capital mainly) is virtually essential for any empirical application. Gift and Marxsen (1984) show that such aggregation is valid under any arbitrary linear weighted averaging provided that the weights do not vary between countries. Using data from two countries almost certainly violates this condition.…”

“…Requirements for each occupational category were derived by head count. This procedure has been used previously by several authors such as Learner (1980) and Baldwin (1971) and has been shown to be legitimate by Gift and Marxsen (1984). In this case, some aggregation of labour requirements by industry was necessary for consistency with the census data.…”

“…It is, therefore, important that any particular skill category is genuinely distinct from another. By the same token, as Gift and Marxsen (1984) comment excessive aggregation risks ignoring important intra-category variations. Care was, therefore, taken in selecting specific occupational categories to choose only those available which represented skills which (a) are likely to involve some time and/or cost for the individual to acquire (thereby ensuring individuals are not freely transferrable between skill categories) and (b) have potential uses in the production of a variety of goods and services.…”