Investment and Hysteresis
企业投资行为违背标准理论，表现为价格大幅高于长期平均成本时才投资，亏损时也不退出。新理论将实物投资类比金融期权，认为等待有价值，解释了这种惯性。
It seems that firms behave contrary to the standard economic theory of investment. We observe that firms do not invest as soon a price rises above long-run average cost; instead firms wait until price rises substantially above long-run average cost. On the downside, firms stay in business for lengthy periods while absorbing operating losses, and price can fall substantially below average variable cost without inducing disinvestment or exit. Recent developments in the theory of investment under uncertainty offer an interesting new explanation. The new approach builds on an interesting analogy between real investments and options in financial markets: In the timing of investment, waiting has positive value because time brings more information about the future prospects of a project. This new approach suggests that textbook pictures of the dynamics of a competitive industry need to be substantially redrawn. More generally, it says that a great deal of inertia is optimal when dynamic decisions are being made in an uncertain environment.