Assessing the willingness of the public to pay to conserve urban green space: the Hangzhou City, China, case.

Introduction

Urban green spaces provide multiple environmental and social benefits, including protection against soil erosion and natural hazards, groundwater protection, air pollution reduction, and amenity values (Jim & Chen, 2006; Organization for Economic Cooperation and Development, 1999; Tyrvainen & Vaananen, 1998). Urban green spaces have become widely recognized as an important component of the infrastructure in urban areas. Increasing urbanization and development have, however, placed urban green spaces under extreme pressure, threatening their abilities to maintain the basic ecological and social functions upon which human existence depends. Furthermore, the distribution of green spaces in cities in China is not homogeneous. Because green spaces may be insufficient and unequally distributed, conservation of these spaces and their multiple functions is becoming an increasing concern for most Chinese cities. Strong and responsive programs similar to those focused on other important components of urban infrastructure, such as streets, sidewalks, sewers, and utilities, are needed to conserve the valuable green spaces of cities. Unfortunately, urban green-space programs are likely to face significant competition for scarce funds.

Urban green spaces in Hangzhou, the study area, are facing the problems outlined above. Hangzhou, the capital of Zhejiang Province in China, is well-known as a tourist city at home and abroad, famous for its natural beauty and historical and cultural heritages. It is located on the lower reaches of Qiantang River in southeast China, at a distance of 180 kilometers from Shanghai. Also known as the National Garden City and the International Garden City, Hangzhou was awarded the China Habitat Prize and the U.N. Habitat Prize, and it is one of the most habitable cities in China. In the popular saying, "Just as there is paradise in heaven, there are Suzhou and Hangzhou on earth," the Chinese compare Hangzhou to a paradise on earth. Thanks to large-scale tree planting and forestation projects in the West Lake Scenic Area and around urban roads, rivers, residential quarters, factories, and companies, the urban green spaces in Hangzhou City are full of vigor and vitality. Through the rapid expansion of urban areas, however, environmental and green-space conservation is under tremendous pressure, partly because governments are stepping back and cutting budgets. Therefore, the public and individuals will need to do more. The availability of funds and support for green-space conservation programs will depend significantly on public awareness, understanding, and knowledge of the benefits of urban green spaces.

A critical step in building public support for urban green-space programs is to assess the knowledge and perception people have of the issues and the importance they grant them. Thus, the objective of the study reported here was to gather information on knowledge about and perceptions of urban green spaces. The authors also examined the relationship between selected socioeconomic variables and the willingness to support urban green-space programs in the metropolitan area of Hangzhou. A contingent-valuation (CV) analysis was conducted; the context was a developing country where economic valuation of urban green spaces remains scarce. The results of the study could provide some reference information that may be of use to the Hangzhou municipality and other city governments in developing countries that wish to conserve urban green spaces.

Methods

The cornerstone economic principle in the assessment of the public value of a proposed program for preventing environmental damage is the concept of "willingness to pay" (Brent, 1995; Carson, 2000). This concept represents the amount of premium that people would be willing to pay to avoid specified environmental damage. Over the past few decades, the contingent-valuation (CV) method has emerged in the field of natural-resource economics as the primary method economists use to elicit public attitudes toward the funding of various environmental programs. The method is a standardized and widely used preference technique for estimating willingness to pay for use or nonuse values of public goods (Mitchell & Carson, 1989). A bibliography compiled by Carson, Wright, Carson, Alberini, and Flores (1994) identifies over 1,600 published articles using the CV method.

The study reported here used the CV survey method to assess the public willingness to pay for conservation of urban green spaces in Hangzhou. The CV method involves constructing a hypothetical market or referendum scenario in a survey. The proposed increase (if respondents pay) or decrease (if respondents do not pay) in the quantity or quality of environmental goods is communicated to respondents in words and with visual aids. Respondents are informed of how much they would have to pay for the proposed quantity or quality. Then the rules of provision are made clear: If you agree to pay, you get the proposed quantity or quality; if you do not pay, you remain at the current quantity or quality level. Respondents use the hypothetical market to state their willingness to pay or to vote for or against a public program at a particular tax price (Loomis, 1996). A National Oceanic and Atmospheric Administration (NOAA) panel concluded that the CV method can produce reliable estimates. Several recommendations were presented, providing the starting point for some administrative and judicial determinations (Report of the NOAA Panel on Contingent Valuation, 1993). The validity and accuracy of a CV study may be enhanced if people are familiar with the issues. Participants should be provided with meaningful information, issues, and methods. In addition, professional interviews are useful (Fisher, 1996).

A survey of households was implemented for a month, beginning the 1st of November, 2005. The study was restricted to the metropolitan area of Hangzhou. A random sampling was obtained first, and then the survey was administered to all residents between 20 and 70 years of age in the sample. Generally, a CV survey can be conducted by in-person interview, telephone interview, or mail. The study used only in-person interviews, however, for cultural and practical reasons. First, it was felt that randomly chosen Chinese citizens would be even less likely than Europeans and Americans to be familiar with the idea of supplying unprompted values for proposed public goods if they were confronted with a telephone interview or mail survey questions. Personal interviews with well-trained interviewers not only can offer the most scope for detailed questions and answers, however, but also can elicit reliable estimates of values. Second, a telephone interview was the least-preferred method because conveying information about the goods being considered may be difficult over the telephone. Finally, a mail survey might be expected to produce low response rates because it fails to attract enough attention against competing stimuli (Green & Tunstall, 1999; Li & Li, 2004).

The survey instrument was a questionnaire. Survey questions were pretested on a random sample of the general public to develop a final valid and reliable questionnaire; the pretest surveyed 120 people. The final survey questionnaire consisted of three parts. The first part included instructions for responding, a definition of urban green spaces, and descriptions of urban green spaces in Hangzhou. According to Jim and Chen (2003), green spaces in cities comprise mainly seminatural areas, managed parks, and gardens, supplemented by scattered vegetated pockets associated with roads and incidental locations. These components were the objects investigated in the study. The second part of the questionnaire consisted of several questions concerning general attitudes toward the benefits and annoyances associated with urban green spaces and the proposed program. Participants were asked to imagine themselves in certain circumstances. The key willingness-to-pay questions for the proposed program were administered; a payment card (PC) method was used. In the third part of the questionnaire, data were gathered on the socioeconomic characteristics of the respondents, including age, gender, income level, residential ownership, and education level.

Before analysis, the authors validated and double-checked the data to minimize errors. Data analyses were conducted with SPSS Release 13.0. Respondents were asked to rank the benefits and annoyances of green spaces as "very important" (2), "important" (1), "do not know/no opinion" (0), and "not important" (-1). The correlation between green space benefits/annoyances and willingness to pay was analyzed with Spearman's correlation. The correlations between the socioeconomic variables and willingness to pay were evaluated with Chi-square analysis. The approximate total value per year for the public of the urban green-space conservation program was then calculated.

Results and Discussions

Response Rate and Respondents' Characteristics

A total of 657 personal interviews were conducted by 30 trained interviewers. These interviews yielded 600 properly completed questionnaires. Fifty-seven questionnaires were excluded by enumerators because of nonresponses to some items or responses of poor quality. The overall response rate was over 91 percent, which is high for residents of large cities (Groves & Couper, 1998). Socioeconomic questions addressed gender, age, education level, residential ownership, and income level. This information was used to determine if any particular characteristic was correlated with willingness to pay for urban green-space programs. The respondents were about evenly distributed between males (51.6 percent) and females (48.4 percent), with an average age of 46 years and a median household income of $5,000 (in U.S. dollars) per year. Most respondents (92.6 percent) had completed high school, and 28 percent had university degrees. Sixty-six percent of respondents said they owned their homes.

Correlation Between Benefits of Green Spaces and Willingness to Pay.

The benefits of green spaces that respondents ranked as the most important reasons for conservation programs were "aesthetic/visual" and "gives shade, reducing glare and energy consumption" (Table 1). Other important benefits included "provides recreation places," "attracts birds and other wildlife," "enhances city/urban climate," "increases privacy," and "increases property value." The benefits that respondents ranked as least important were "fall color marking changes in season" and "flowers in tree." These findings probably reflect the fact that most tree species on public property do not have showy flowers (according to a tree inventory of the city). Other benefits that were ranked low include "stormwater control," "control of dust/particulate matter," and "wind control." The low ranking of these benefits may be attributed to the fact that they are not visible and readily observable or that these roles of green spaces are not well understood by the public.

All of the green-space benefits identified in the study were positively correlated with a willingness to pay additional taxes for the conservation of green spaces. Respondents who assigned high importance to the individual benefits of green spaces also tended to be willing to pay additional amounts for conservation. The benefits that were highly correlated with willingness to pay were "aesthetic/visual"; "provides recreation places"; "attracts birds and other wildlife"; "increases property value"; "gives shade, reducing glare and energy consumption"; "reduces noise"; "fall color marking changes in season"; "flowers in tree"; "wind control"; "increases privacy"; "reduction of gaseous air pollution"; and "control of dust/particulate matter." By contrast, "stormwater control" and "enhances city/urban climate" were weakly correlated with willingness to pay. These results suggest that respondents' willingness to pay increases with more readily visible and recognizable benefits of urban green spaces. Thus, the less commonly known and understood benefits should be emphasized in outreach and educational programs to enhance public perception and therefore increase public willingness to support urban green-space programs.

Correlation Between Annoyances from Green Spaces and Willingness to Pay

The annoyances associated with green spaces that respondents ranked as most important were "causes some allergies," "limbs falling from tree," and "sidewalk damaged by tree roots" (Table 2). The annoyances that were ranked as least important were "they are unsightly in appearance when not maintained," "branches or suckers grow around the base of the tree," "diseased trees," and "darkened streets creating issues of security."

Overall, the annoyances were rated as less important than the benefits. The strongest annoyance was rated on average as "slightly important" to "moderately important." This result suggests that, although problems may occur with urban green spaces, the annoyances generally are less prominent than the benefits. As a result, residents appear to tolerate what generally are perceived as annoyances correlated with urban green spaces.

A majority of the individual annoyances associated with green spaces correlated negatively with the willingness to pay for conservation. These annoyances were "darkened streets creating issues of security," "tree roots clog sewers," and "sap drips from tree." But the annoyances "leaves, flowers, fruits, or seed pods fall from tree," "limbs falling from tree," and "causes some allergies" did not appear to correlate with willingness to pay. These results indicate that the presence of what are commonly considered annoyances associated with green spaces did not actually reduce willingness to pay.

Correlation Between Socioeconomic Variables and Willingness to Pay

The correlation between willingness to pay and basic socioeconomic variables such as gender, age, income, ownership, and education were tested with Pearson Chi-square analysis (Table 3). The amounts respondents were willing to pay differed significantly by gender, income level, and residential ownership. More than 42 percent of female respondents were willing to pay between $12 and $24 per year in additional taxes, as opposed to 31 percent of male respondents. More males (25 percent) than females (18 percent), however, were willing to pay more than $24 per year in additional taxes for the conservation of urban green spaces. Approximately 36.3 percent of respondents were willing to pay between $12 and $24 per year across income levels. The willingness to pay more than $24 per year increased with income level. The upper limit of what people were willing to pay was $60 per year. More homeowners (81.4 percent) than renters (60.6 percent) were willing to pay additional taxes. Among homeowners, 56.7 percent were willing to pay more than $12 in additional taxes. By comparison, approximately 40 percent of renters were willing to pay more than $12. The price of housing in Hangzhou has gone up steadily in recent years, and the average housing price in urban and suburban areas of Hangzhou exceeds 10,000 yuan (some $1,200 in U.S. dollars) per square meter. Therefore, renters are facing economic pressures that are too heavy to allow them to pay additional taxes. The other socioeconomic variables, and age and education level, did not significantly correlate with willingness to pay (Table 3).

Perception of Importance of the Urban-Green-Space Program

When the respondents were asked about how important the conservation of urban green spaces is, 89 percent indicated that conserving their green spaces is very important. Of this group, approximately 84 percent (which represents approximately 75 percent of all respondents) were willing to pay additional taxes to conserve urban green spaces. The remaining 25 percent selected the following reasons for being not willing to pay more: 1) The city should conserve green spaces using other taxes. 2) The city has more important problems than conserving green spaces. 3) I did not want to put a dollar value on conserving green spaces. 4) I cannot afford to pay anything. 5) I object to the way the question is asked. 6) Conserving green spaces is not worth anything to me.

There is a further reason for the willingness of the majority to pay. As mentioned above, Hangzhou City has a high level of urban green spaces, and the living environment in Hangzhou is habitable and restful. Consequently, most residents are completely satisfied with the urban environment and hope that the green spaces can be conserved better as far as possible. This finding is consistent with the results of a 2005 survey, China Cities and City People's Sense of Happiness. According to Professor Xi Kaiyuan of the Chicago Business School, the results of that survey show that people in Hangzhou City felt "the happiest" and that most of them were unwilling to live outside Hangzhou (Li, 2006).

Estimation of Willingness to Pay at the Population Level

The authors calculated the total public value of the proposed program to provide at least a preliminary evaluation for governmental policy options. As described earlier, the sample selected is representative of the population in terms of demographic characteristics such as residential ownership, gender, age, income, and education. In addition, well-trained interviewers implemented the survey in the field to ensure the representativeness of the sample. Thus, the values obtained from the sample can reliably be expanded to the general population. The authors multiplied the estimated mean willingness to pay per household by the total number of households in Hangzhou to estimate the total public value per year of the conservation program for urban green spaces. The mean willingness to pay per household was $24.4, and the total number of households in Hangzhou in 2004 was about 630,000 (Hangzhou Municipal Bureau of Statistics, 2005). Therefore, the total public value per year is about $15.4 million. This result also indicates that the residents in Hangzhou place a high value on the conservation of urban green spaces. Practically speaking, the total public value can be compared with the conservation costs of urban green space or the value of alternative land use in urban planning projects. If the conservation of urban green space is socially profitable, appropriate conservation policy should be made and implemented immediately.

Conclusions

The "voice of the people" has always been important in the political decision-making process in a democratic society. The public is one of the greatest resources a city has for developing and implementing green-space policies and programs. Residents know the city's land and natural attributes more intimately than a government ever will. Their numbers make them more pervasive than the largest government agency The involvement of the public is crucial to the establishment and implementation of a sound and effective green-space conservation program. Therefore, a clearer understanding of the public perceptions of the benefits and annoyances of green spaces is needed.

The willingness to pay for the conservation of urban green spaces can improve the development and implementation of sustainable urban green-space programs. In the study reported here, the CV method was used to assess the public value attached to urban green spaces in Hangzhou. The mean of what people are willing to pay was estimated for the proposed program. A willingness to pay additional taxes to support urban green-space programs was correlated with the most commonly perceived benefits of green spaces. By contrast, properties commonly perceived as annoying were negatively correlated with willingness to pay The socioeconomic variables gender, income, and residential-ownership status contributed to willingness to pay specific levels of support, although other basic socioeconomic variables showed no significant correlations with willingness to pay. This finding needs to be confirmed by study of a larger population.

The results of the study reported here provide preliminary qualitative and quantitative information on the public value attached to the urban green spaces in Hangzhou. The results can be useful in policy making in urban development planning. Qualitatively speaking, initiatives that set out to build support for urban programs must pay significant attention to the more commonly recognized and visible benefits. For instance, the "aesthetics/visual" dimension of the program could be emphasized in selecting trees for planting and replacement projects whenever and wherever feasible. Quantitatively speaking, the total public value per year for the conservation program for urban green spaces is approximately $15.4 million. The main preliminary results indicate that concerns are increasing and that residents are willing to shoulder the burden to conserve urban green spaces. In addition, the amount residents are willing to pay is correlated with total household income. Therefore, tiered solicitation that takes into account the different income levels in the city might be a more effective tool for seeking support for urban green-space programs than traditional techniques.

Corresponding Author: Zhiyi Bao, Professor, Zhejiang University, Department of Horticulture, Huajiachi Campus, No.268, Kaixuan Road, Hangzhou, Zhejiang, China 310029. E-mail: [e-mail].

REFERENCES

Brent, R.J. (1995). Applied cost-benefit analysis. Cheltenham, UK: Edward Elgar Publishing Ltd.

Carson, R.T. (2000). Contingent valuation: A user's guide. Environmental Science & Technology, 34, 1413-1418.

Carson, R.T, Wright, J.L., Carson, N., Alberini, A., & Flores, N. (1994). A bibliography of contingent valuation studies and papers. La Jolla, CA: Natural Resource Damage Assessment, Inc.

Fisher, A. (1996). The conceptual underpinnings of the contingent valuation method. In D.J. Bjornstad & J.R. Kahn (Eds.), The contingent valuation of environmental resources (pp. 19-37). Cheltenham, UK: Edward Elgar Publishing Ltd.

Green, C.H., & Tunstall, S.M. (1999). A psychological perspective. In I.J. Bateman & K.E. Willis (Eds.), Valuing environmental preferences: Theory and practice of the contingent valuation method in the U.S., EU and developing countries (pp. 207-257). Oxford: Oxford University Press.

Groves, R., & Couper, M. (1998). Nonresponse in household interview surveys. New York: John Wiley & Sons, Inc.

Hangzhou Municipal Bureau of Statistics. (2005). 2004 Hangzhou statistical yearbook. Beijing: China Statistics Press.

Jim, C.Y., & Chen, S.S. (2003). Comprehensive greenspace planning based on landscape ecology principles in compact Nanjing city, China. Landscape and Urban Planning, 65(3), 95-116.

Jim, C.Y., & Chen, W.Y. (2006). Recreation-Amenity use and contingent valuation of urban greenspaces in Guangzhou, China. Landscape and Urban Planning, 75(1-2), 81-96.

Li, H.P., & Li, H. (2004). Methods of social survey in urban planning. Beijing: China Architecture & Building Press.

Li, J.J. (2006). Shanghai voted most desirable city to move in. Retrieved May 5, 2006, from http://www.chinanews.cn//news/2005/2006-01-16/17523.html.

Loomis, J. (1996). Measuring the economic benefits of removing dams and restoring the Elwha River: Results of a contingent valuation survey. Water Resources Research, 32, 411-447.

Mitchell, R.C., & Carson, R.T. (1989). Using surveys to public goods: The contingent valuation method. Washington, DC: Resources for the Future.

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Although most of the information presented in the Journal refers to situations within the United States, environmental health and protection know no boundaries. The Journal periodically runs International Perspectives to ensure that issues relevant to our international constituency, representing over 60 countries worldwide, are addressed. Our goal is to raise diverse issues of interest to all our readers, irrespective of origin.

Bo Chen

Zhiyi Bao, Ph.D.

Zhujun Zhu, Ph.D.

TABLE 1 Mean Importance of Benefits Associated with Green Spaces

Green-Space Benefits                    Rank*  Importance**

Aesthetic/visual                         1     1.86
Gives shade, reducing glare and energy   2     1.81
  consumption
Provides recreation places               3     1.72
Attracts birds and other wildlife        4     1.66
Enhance city/urban climate               5     1.66
Increases privacy                        6     1.64
Increases property value                 7     1.59
Reduces noise                            8     1.56
Reduction of gaseous air pollution       9     1.56
Storm water control                     10     1.47
Control of dust/particulate matter      11     1.41
Wind control                            12     1.38
Flowers in tree                         13     1.18
Fall color marks changes in season      14     1.10

*Ranking is based on the order of the means.
**Means are based on the following scale: 2 (very important), 1
(important), 0 (do not know/no opinion), and--1 (not important).

TABLE 2 Mean Importance of Annoyances Associated with Green Spaces

Green-Space Annoyances                              Rank*  Importance**

Causes some allergies                                1      0.62
Limbs falling from tree                              2      0.61
Sidewalk damaged by tree roots                       3      0.48
Sap drips from tree                                  4      0.27
Leaves, flowers, fruits, or seed pods falling from   5      0.24
  tree
Tree roots clog sewers                               6      0.22
Tree falling across power lines                      7      0.05
Insects in tree                                      8     -0.02
Darkened streets creating issues of security         9     -0.23
Diseased trees                                      10     -0.36
Branches or suckers growing around base of tree     11     -0.49
They are unsightly in appearance when not           12     -0.58
  maintained

*Ranking is based on the order of the means.
**Means are based on a scale of 2 (very important), 1 (important), 0
(do not know/no opinion), and--1 (not important).

TABLE 3 Percentage of Respondents Willing to Pay Additional Taxes, by
Socioeconomic Variable

Variable                               None  <$12  $12-$24  >$24

Gender
  Male                                 28.7  14.8  31.3     25.2
  Female                               24.9  15.0  42.1     18.0

Age
  20-30                                16.7  18.1  43.5     21.7
  31-50                                28.0  15.2  33.7     23.1
  51-70                                25.1  14.6  40.6     19.7

Income Level
  [less than or equal to]$2,000        22.8  16.5  45.9     14.8
  $2,001-$3,000                        26.3  17.5  40.6     15.6
  $3,001-$5,000                        26.6  11.8  39.7     21.9
  $5,001-$8,000                        25.9  12.4  38.2     23.5
  [greater than or equal to]$8,001     20.0  12.1  30.1     37.8

Residential Ownership
  Homeowner                            18.6  24.7  37.8     18.9
  Renter                               39.4  31.4  20.5      8.7

Educational Level
  Elementary school graduate or lower  31.6  15.4  34.3     18.7
  Junior high school graduate          20.0  30.0  50.0      0.0
  Senior high school graduate          18.5  22.6  47.1     11.8
  University graduate or beyond        18.8  13.3  41.1     26.8