NRP Revenues = ∑ NRP Pr ice (1.1)
WTP≥NRP Pr ice
Gate Revenues = ∑NRP Price (1.2)
WTP<NRP Pr ice
Total NRP revenues are calculated by multiplying NRP price by the total number of households with
a maximum WTP greater than the price (i.e., all households that would purchase the pass). Total gate
revenues are calculated by summing up maximum WTP for all households with WTP less than the NRP
price (i.e., all households that would not purchase the pass and instead pay at the gate). This method for
estimating total gate revenues assumes that (i) households do not systematically over- (or under-) estimate
the number of trips to federal recreation sites, and (ii) they do not purchase the pass for convenience or
stewardship purposes. The effect of relaxing these assumptions is discussed in more detail below.
4. Survey Design
Our goal with the valuation survey was to link the NRP valuation exercise to real choices and real
outside options; respondents answered the new valuation question after thinking about the status quo and
their familiarity with the NPP and GEP. Our intent was to keep the survey realistic, simple, and quick
while still generating reasonable value estimates. When possible, we followed general guidelines
established by recent research in this area and by the NOAA panel (Arrow et al., 1993) on non-market
valuation methods. Given time constraints and the scale of the project, however, the NOAA panel’s
recommended face-to-face survey was infeasible. Instead, we conducted a nationwide telephone survey
between February and April of 2006, using computer-aided telephone interviewing. The survey methods
were reviewed and approved by the U.S. Office of Management and Budget.
The survey sample consisted of two independent strata. The first stratum was sampled using a
national Random Digit Dialing (RDD) draw of households with landline telephones. To enhance the
precision of estimates from this part of the sample, it was pre-stratified by the 9 major geographic
divisions defined by the U.S. Bureau of the Census, and post-stratified to reflect Census Bureau