The Economic Value of Water and Ecosystem Preservation

This average number of trips from this equation was estimated as 13.6 which
is about half the actual average of 27.3. The average travel cost reported from
the survey data is $508 for the aggregated data set. Equation 1 was then used to
estimate the number of trips for the average visitor for incremental price
increases ranging from $1 up to $1,900. The average consumer surplus was
calculated as $1,136 for the aggregated data set.
The data was disaggregated by Texas residents and non-residents. This was
done as it appeared as if some respondents reported travel costs that included
general costs for travel to Texas instead of solely costs for the daily nature trip.
The average travel costs were given as $231 for Texas residents and $1,024 for
non-Texas residents.
Regressions were run on each data set with the TX_home variable omitted.
The resulting equations had an adjusted r-square of .22 for the Texas residents
and a .20 for the non-Texas residents. Using the same method as described
above the average consumer surplus for Texas residents was estimated as $273
and for non-Texas residents it was estimated as $13,060. A graph of the three
estimated demand curves is presented in Figure 4-2.
Figure 4-2. Estimated individual demand curves for eco-tourism
Travel Cost ($)
1600
1400
1200
1000
800
600
400
200
0
0 10 20 30 40 50 60 70 80 90 100
Trips
37
All
Texans
Non Texans