(a) Estimating use—(^) Use estimating models, (i) 

 The preferred method for estimating use is a use 

 estimating model (UEM) that relates use at a pro- 

 posed site to distance traveled, socioeconomic fac- 

 tors, and characteristics of the site and alternative 

 recreation opportunities. Use estimating models are 

 based on data gathered at an existing site or on a 

 cross section of existing sites with the resultant sta- 

 tistical coefficients used to estimate use at a pro- 

 posed site. Factors that influence demand for rec- 

 reation, such as characteristics of user populations 

 and availability of alternative opportunities, are ex- 

 plicity taken into account by variables in the model. 



(ii) Application of an existing UEM to a proposed 

 site involves the following steps: (A) Identify the 

 areas of origin for the proposed project (use of 

 counties or parts of counties as origin areas facili- 

 tates oathering of data in subsequent steps); (B) 

 compute measures of the explanatory variables in 

 the use equation for each origin area and for each 

 year an estimate is required; (C) calculate use from 

 each area and for each year; and (D) aggregate 

 use from each area to get estimated annual use. 



(2) Similar project use estimation, (i) The similar 

 project procedure is based on the concept that rec- 

 reation demand for a proposed project can be esti- 

 mated by observing the visitation patterns at one or 

 more existing projects with similar resource, oper- 

 ation, and anticipated recreation-use characteris- 

 tics. The procedure involves the graphic or statisti- 

 cal matching of the recreation site alternatives 

 under study with existing water resource projects 

 and recreation resource areas for which use statis- 

 tics and other information are known. The objective 

 of the similar project procedure is to obtain as 

 close a match as possible in type, size, and quality 

 of project; market area demographic and socioeco- 

 nomic characteristics; the existence and location of 

 competing recreation opportunities; and other 

 demand influencing variables. 



(ii) The most efficient and technically sound simi- 

 lar project procedure is based on per capita use 

 curves (i.e., regression curve relating per capita 

 rate of use to travel distance) from which use esti- 

 mates are derived. Per capita use curves have 

 been estimated for 52 existing reservoirs.' An over- 

 view of the methodology adapted from Brown, et 

 al., is provided below. 



(iii) Briefly stated, use of the similar project pre- 

 diction method involves the following steps: 



(A) Evaluate the characteristics of a proposed 

 project or area under study. 



(B) Select a similar project or area by comparing 

 characteristics of the proposed project with availa- 



ble information for existing sites; include evaluation 

 and comparison of the respective recreation market 

 areas. 



(C) Adjust the per capita use curve to account for 

 the differences between the similar project and the 

 proposed project. 



(D) Determine the county populations within the 

 market area for the year in question and derive per 

 capita use rates for each county population by 

 measuring road-mile distance from the project to 

 the center of the most populated city within the 

 county (proxy for centroid of county population). 



(E) Multiply the contribution from each county per 

 capita rate by county population, and sum to get 

 total use. 



(F) Determine the percentage of total use that 

 the foregoing estimate represents. If 100 percent, 

 use as is; if less, adjust accordingly. 



(iv) A critical shortcoming of this similar project 

 method is the subjectivity inherent in the manual 

 adjustment of the per capita use curve required to 

 account for demand factors other than travel dis- 

 tance. The reliability of the method can be en- 

 hanced through experience, but it cannot be ex- 

 pected to approach the reliability of the more so- 

 phisticated statistical models. 



(b) Deriving demand in the travel cost method. 

 (1) The travel cost method is based on the corre- 

 spondence between increasing the distance from 

 areas of origin to the site and increasing the cost or 

 price of recreation at the site. The second step of 

 the procedure consists of calculating total use at 

 different incremental distances (prices); it is based 

 directly on use estimator models or per capita use 

 curves. The result is a demand curve for the site 

 being evaluated that relates "prices" to total visits. 

 Distances are converted to dollar values using per 

 mile conversion factors reflecting both time and 

 out-of-pocket travel costs. The area under the 

 demand curve plus any user charges or entrance 

 fees measure the recreation benefits attributable to 

 the site. The procedure is described in detail below. 



(2) The estimate of recreation use for a project 

 derived from application of a per capita use curve 

 or UEM model yields an initial point on a resource's 

 demand curve. This point is the quantity of use that 

 would be demanded at a zero price. For example, 

 assume that the appropriate per capita use rates 

 have been estimated as follows: 



' Brown. R el al . P/an Formation and Evaluation Studies: Recreation, Vol. II. U.S. 

 Army Engineer Institute tor Water Research. 1974. 



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