International trade economists made seminal contributions to general equilibrium theory, moving away from an emphasis on existence of equilibrium to algebraic formulations which enabled us to characterize key relationships between parameters and variables, such as that between tariffs and...

Producer services such as managerial and engineering consulting can provide domestic firms with the substantial benefits of specialized knowledge that would be costly in terms of both time and money for domestic firms to develop on their own. These intermediate services are often non-traded, or...

The comparative advantage of many cities is based on their efficiency in the production of ‘functions’, e.g., business services such as finance, law, engineering, or similar functions that are used by firms in a wide range of sectors. Firms that use these functions may choose to source them...