The Determination of Recreation Values of Jamshidieh Park in Tehran by Using Contingent Valuation Method

Introduction
Nowadays, the main environmental economy subject, which is almost publicly accepted, is the fact that the environment is inseparable from the economy and any changes in one may affect directly the other one. In other words, no economic decision is made without influencing the natural and artificial environment and no environmental change occurs without economic influences.
United States and Europe countries focus on CV method to determination of recreation values.  Lee has determined recreation values of South Korea national park 10.54$ per year. Applying CVM, calculated the recreation values of ecosystem service 67.44 $ per year of family for Bursa State in Turkey. Baral et al (2008) determined recreation value by using CV. Given this backdrop, the main purpose of this research is the determination of recreation values of Jamshidieh Park in Tehran by Using Contingent Valuation Method and SHAZAM software on 2011. Partial goals are including:
1- Determination of Demographic characteristics of Jamshidieh Park visitors.
2- Determination of effective Factors on willingness to pay for Jamshidieh park visitors.
3-Determination of recreation values of Jamshidieh Park and estimation of WTP as Park admission fee.
Materials and methods
This research employed CVM, which has been commonly used as one of the standard approaches to measure the economic values of non-market goods, such as recreation resources, wildlife, and environmental quality goods. The CVM relies on the stated intentions of individuals’ willingness-to-pay (WTP) for recreation resources or activities, contingent on hypothetical changes in the quantity or quality of environmental amenity. In the other words, the CVM basically attempts to ascertain from respondents what they would be willing to pay under certain hypothetical market scenarios.
The target population was Jamshidieh Park visitors that they had revenue and could decide about payment of admission fee. A complete random sampling method was used and sample size was determined by means of Cokran formula to be 210 Jamshidieh Park visitors. This research used a survey design and face to face interview technique as means of data collection.
The questionnaire was designed in two sections consisting of: A) personal variables, socioeconomic characteristics respondents such as age, gender, occupation, education level, marital status, family size, house status and monthly income; B) visitor’s willingness to pay for recreation values of Jamshidieh Park by means of Double-bounded Dichotomous Choice Technique.  A multilevel binary response model with multiple responses is fitted, allowing inclusion of a "yes/no" WTP question not associated with a particular bid level in the statistical model. Further, issues concerning potential biases within the DC framework can be examined directly using such an approach.
Independent variable for determination of recreation value is accepting probability of a suggested admission fee for recreation. It is assumed that the individual will accept a suggested admission fee for recreation, to maximize his or her utility under the following condition.
                                                               (1)
Here, U is the indirect utility; INC is income, BID is an offer (admission fee), S is other socio-economic characteristics affecting individual preference, and  and are the identically, independently distributed random variables with zero means. The utility difference (du) can be described as follows:
                                                                                        (2) 
Double-bounded questionnaire structure in studying the WTP of individuals has a dependent variable with dual selection. Hence, Logit model for studying the effect of different descriptive variables on the amount of WTP of visitors was used to determine the recreation value. Logit model parameters  were estimated by Maximum Likelihood Model (MLE). Hence, E (WTP) is expressed as relation 3:
                (3)
 
 
 
E (WTP) is the expected value of WTP and  is the adjusted intercept which was added by the socio-economic term to the original intercept term of .
Results and discussion
In order to estimate the recreational value of Jamshidieh Park, some questionnaires were chosen in which the respondents had monthly independent income. Therefore, 200 of the total distributed questionnaires were selected and analyzed. In fact, the respondents were asked about the cost they were willing to pay for the Recreational Value of Jamshidieh Park from their monthly income.
About 88% of the respondents are male and 75% are married. The demographic and socioeconomic characteristic is depicted in table (1).
Table 2: respondent socio-economic characteristic (n=200)





Variable


Mean


Standard deviation


Min


Max




Age


36.46


12.76


18


71




Monthly expenses (RLS)


6279000


4222811


3000000


25000000




Number of park visit (per year)


7.9


5.06


1


50




park visit duration


2.64


1.02


1


6




Family size


2.98


1.61


1


7





 
As depicted in table (2), 124 individuals (62%) did not accept the first offer and they were not willing to pay 10000 RLS for each member of their family for entrance fee and using the Recreational Value of the Jamshidieh Park from their monthly income. 76 individuals (38%) accepted. When the lower price (7000 RLS) was offered, 36 individuals (18%) didn’t accept the second offer and asked for a lower price. However, 88 individuals (44%) accepted it.
Table 3: Response status to proposed price for jamshidieh park recreational value (n=200)





Acceptance status


First proposed price
(10000 RLS)


Second proposed price
(7000 RLS)


Third proposed price
(20000 RLS)




Acceptance of proposed price


number


76


88


36




percent


38


44


18




Reject of proposed price


number


124


36


40




percent


62


18


20




Total


number


200


124


76




percent


100


62


38





 
Results of the Logit Model for the Recreational Value of Jamshidieh Park are available in Table (3). According to the results, the variables of proposed price, marital status, hostile status, the duration of each use, the number of members of families affect the probability of acceptance of proposed price for the recreational value of Jamshidieh Park. The estimated coefficient of the offer factor which is the most important distribution factor of the probable WTP for the recreational value has become statistically 
meaningful at 5% level with the expected minus sign. This shows that under the scenario of the assumed market, increase in the offered price will lead to decrease in the probability of “yes” in WTP. The estimated income coefficient in the Recreational Value has become statistically meaningful at the level of 5% and the sign was plus as expected which shows that the probability of “yes” in WTP increases with the rise in income. The coefficient of size of the household has become meaningful with a minus sign at the level of 5%. The minus sign shows that the larger the size of the household the more likely the answer “yes” in WTP.
Table 1:The results of the Logit Model for the Recreational Value of Jamshidieh Park





Variable


coefficients


T Statistic


Change in probability


Marginal effect




Age


-0.022


-0.64


-0.39


-0.0055




Sexuality


0.42


0.53


0.18


0.1




Marital status


2.8


2.78^**


0.97


0.67




park visit duration


0.000000043


0.57


0.13


0.00000001




House status


0.97


1.68^*


0.31


0.24




Number of park visit (per year)


-0.035


-1.033


-0.13


-0.009




Monthly income


0.000006


4.3^**


0.92


0.000042




size of the household


-0.39


-2.15^**


-0.8


-0.14




Proposed price


-0.0016


-2.93^**


-1.05


-0.00004




constant


-2.77


-1.66


-1.34


-




Log- Likelihood Function = -47.32
Likelihood Ratio Statistic = 43.97
Probability (L/R/ Statistic) = 0. 0000
Percentage of Right Predictions = 78.24
CRAGG-UHLER R² = 0.47





Estimating the parameters of the Logit Model, the average of expected WTP which is equal to the Recreational Value of the Jamshidieh Park was estimated 23448 RLS for each visitor annually:
 
If the amount of WTP for each family or visitor was clear, the Recreational Value of each hectare of Jamshidieh Park can be estimated through the following formula: (The total number of the visitors * the average of the WTP)/area = the Recreational Value of each hectare of the Jamshidieh Park. It is 203895652 RLS and the average of Recreational Value for family was 844128 RLS.
Conclusion
This study discussed about determination of recreation values of Jamshidieh Park and measure of individual’s willing to pay for visiting this park based on contingent valuation method and double-bounded dichotomous choice questionnaire. To investigate the effect of explanatory variables on individual’s willing to pay Logit model was used and its parameters are estimated based on the method of maximum likelihood. Results showed that proposed price variable, marital status, house status, monthly income, and size of the household affect the probability of acceptance of the proposed price. The mean of willingness to pay for recreation value of this park is RLs 23448 per visit. Also about 86% of Jamshidieh Park visitors were willing to pay for entrance fee of the park. According to the results considering the population intensity, air pollution and the importance of citizen’s happiness, the preservation of parks is considered a serious fact in Tehran.