The author discusses several issues that instructors of introductory macroeconomics courses should consider when introducing imports in the Keynesian expenditure model. The analysis suggests that the specification of the import function should partially, if not completely, be the result of a simple discussion about the spending and import behaviors of the household, firm, and government sectors. The analysis also indicates that instructors who use certain import functions that are in some introductory textbooks will inadvertently impose restrictions on the model and potentially confuse students. The author examines several implications of the specification proposed by Robert Cherry (2001) and shows how the restrictions imposed by Cherry's specification make it difficult for instructors to present certain types of economic events and policies. The import function discussed here avoids these restrictions and allows instructors to present more easily certain types of examples.
