The equilibrium conditions for an economic system that produces output with several factors of production and which is subject to technological constraints are derived. Optimization of either output minus cost or integrated utility yields the conditions that output elasticities must be equal to...

Feenstra and Ma (2008) develop a monopolistic competition model where firms choose their optimal product scope by balancing the profits from a new variety against the costs of "cannibalizing" sales of existing varieties. While more productive firms always have a higher market share, there is no...