Recent theoretical developments have incorporated endogenous multinational firms into the general-equilibrium model of trade. One simple taxonomy separates the theory into vertical' models in which firms geographically separate activities by stages of production and horizontal' models of...

"The fundamental unit of production in microeconomics is the firm, and this mirrors reality in the United States and United Kingdom. But elsewhere, business groups can be the more important unit, for business strategy is often formulated at the business group level, not the firm level. In many...

We explore the managerial implications and economic consequences of platform sharing under models of horizontal and vertical product differentiation. By using a common platform across different products, firms can save on fixed costs for platform development. At the same time, platform sharing...