A Note on Supply Side Option Value
指出，当供给概率从p1增加到p2时，即使收入的价格弹性为零，期权价值的符号也不确定，挑战了以往研究中认为期权价值为正或负的结论。
There has recently been a resurgence of interest in the concept of option value (Anderson 1981; Freeman 1984, 1985; Graham 1981; and Smith 1983, 1985). Two articles in this journal (Brookshire, Eubanks, and Randall 1983 and Bishop 1982), have suggested that option value is a more meaningful concept when demands are certain, but future availability of the resource is uncertain. A change which involves exchanging supply uncertainty for supply certainty will, for the risk averse consumer, be worth more than the change in expected consumer's surplus. The amount more will be the worth of the risk reduction or the option value. It will be unambiguously positive. Freeman (1985) has pointed out that exchanging supply uncertainty for supply certainty is just one of the possibilities, and that at least in some cases what is assumed with respect to the price flexibility of income for the good can make a difference. The objective of this note is to show that even when the price flexibility of income for the good is zero, the sign of option value will be ambiguous in the case where the change involves an increase in the probability of supply fromp Ito P2, with 0 < p, <P2 < 1. This is Freeman's (1985) Case D, and also the case which is the basis for Brookshire, Eubanks, and Randall's empirical analysis. However, what is shown here is that neither Freeman's (1985) assertion of a negative option value, nor Brookshire, Eubanks, and Randall's assertion of a positive option value, can in general be justified for this case. A Model with Supply Uncertainty