Abstract: | We develop dual approaches to quantity and price relationships of production in a general multisectoral model with sector‐specific externalities. The production of each good exhibits socially constant returns to scale but privately decreasing returns. We find that the Stolper‐Samuelson theorem holds for factor intensity ranking from the social perspective and that the Rybczynski theorem holds for factor intensity ranking from the private perspective. The price‐output dual fails to hold in general. Moreover, we re‐establish the Heckscher‐Ohlin theorem in the two‐sector case, as well as the factor endowment–factor price and price‐output comparative statics in the high‐dimension case under proper conditions. |