Technological linkages, market structure, and production policies
论证产业政策需同时考虑技术关联和目标产业的市场势力，最优政策可能包含补贴和税收，但若不可行，对外部性活动进行固定或单位补贴未必可取。
Proponents of industrial policy argue that key industries merit subsidies because they generate beneficial externalities. We show that policy must reflect both technological linkages and market power in the target industries, the interaction of which may produce an optimal policy including both subsidies and taxes on target industries. The optimal policy combination may not be politically or administratively feasible. If so, we show that it may not be desirable to subsidize output in the externality-generating activity on either a fixed or per-unit basis. Thus, technological linkages alone do not lead to the presumption that the externality-generating activity should be subsidized.