22
Footnotes
1. “Choke” prices are the minimum prices that choke off demand to zero; thus they are
the price on the demand curve (whether Hicksian or Marshallian) for which
quantity equals zero. In measuring access values, Hicksian choke prices are used;
they are infinite for models where quantity consumed approaches zero
asymptotically with price.
2. This latter case is the problemmatic one, for all demand systems, as it implies the
good is a necessity, which is implausible for specific recreation activities; thus
one would not expect to see this case in practice.
3. The normalized marginal value of time, 38(p,t,M,T), is the ratio of the marginal utility
of time and the marginal utility of money in the normalized choice model and, as
such, is potentially a function of all variables in the choice problem. Larson and
Shaikh (2001) show that 38(p,t,M,T,s) is homogeneous of degree zero in (p,M),
(t,T), and (p,t,M,T).
4. With 38 independent of the budget arguments, one can measure the money
compensating variation of welfare change either as a difference in the money
expenditure function or as a difference in full expenditure, since the term 38 ∙ T8
does not change with money prices.
5. Because the truncation was at the same threshold, 0, it is not possible to estimate a
scale coefficient so it is normalized to 1.
6. This was typically the case for other demand models explored using these data as
well.
7. To give a sense for variation in these elasticities due to differences in demand
covariates, the standard errors of the sample means are also provided in Table 4.
8. The corresponding Hicksian elasticities (not shown) are symmetric as expected and
required by theory.