Stated preferences for improved air quality management in the city of Nairobi, Kenya
Abstract
The study uses contingent valuation (CV) framework to assess individuals’ preferences for improved air quality management through motorized emission reductions in the city of Nairobi, Kenya. A conventional payment card (PC) is used to draw preferences from individuals in order to estimate the mean and the median willingness to pay (WTP) for air quality improvements in the city. Through interval regression analysis, the study finds that individuals are, on average, willing to pay Kshs. 396.57 ($4.67) and a median of Kshs. 244.94 ($2.88) to improve air quality management in the city. These amounts are found to increase with male gender, individuals’ income, certainty about future income and residence in an urban area. These amounts, however, decline with age, residential distance from nearby roads, and motor vehicle ownership. On the whole, the study shows significant public support towards improved air quality management in the city, which is of vital importance for effective formation and implementation of air quality management programmes.
References
Ababio, O.Y. (2003). New school chemistry. Onitsha: Africana-FEP.
Ackerman, M., Davies, T., Jefferson, C., Longhust, J., & Marquez, J. (2002). Comparison of diesel and hybrid vehicle emissions by computer modelling. Urban Transport, VIII, 471-480. doi:10.2495/UT020461.
Amin, A.T.M.N. (2009). Reducing emissions from private cars: Incentive measures for behavioural change. Nairobi, Kenya: UNEP. Retrieved Jun, 15, 2015, from http://www.unep.ch/etb/publications/Green%20Economy/Reducing%20emissions/UNEP%20Reducing%20emissions%20from%20private%20cars.pdf
Arrow, K., Solow, R., Portney, P.R., Leamer, E.E., & Radner, R.H. (1993). Report on the NOAA Panel on contingent valuations, natural resource damage assessment under the Oil Pollution Act of 1990. Federal Register, 58, 4601-4614.
Asian Development Bank. (2003). Reducing vehicle emissions in Asia. Manila, Philippines: Asian Development Bank.
Bateman, I., Carson, R.T., Day, B., Hanemann, W.M., Hanley, N., & Hett, T. (2002). Economic valuation with stated preferences: A Manual. Cheltenham, UK: Edward Elgar.
Brouwer, R. (2009). Stated preference uncertainty: signal or noise? Amsterdam: Institute for Environmental Studies, VU University Amsterdam.
Cadle, S.H., Croes, B.E., Minassian, F., Natarajan, M., Tierney, E.J., & Lawson, D.R. (2004). Real-world vehicle emissions: A summary of the Thirteenth Coordinating Research Council on-road Vehicle Emissions Workshop. Journal of the Air and Waste Management Association, 54(1), 18-23.
Cameron, T.A., & Huppert, D.D. (1989). OLS versus ML estimation of non-market resource values with payment card interval data. Journal of Environmental Economics and Management, 17(3), 230-246. doi:10.1016/0095-0696(89)90018-1.
Carlsson, F., & Johansson-Stenman, O. (2000). Willingness to pay for improved air quality in Sweden. Journal of Applied Economics, 32(6), 661-669. doi:10.1080/000368400322273.
Carson, R.T. (2000). Contingent valuation: a user’s guide. Environmental Science and Technology, 34(8), 1413-1418. doi:10.1021/es990728j.
Central Bureau of Statistics - CBS. (2009). Economic Survey 2009. Nairobi, Kenya: Central Bureau of Statistics.
Colvile, R.N., Hutchinson, E.J., Mindell, J.S., & Warren, R.F. (2001). The transport sector as a source of air pollution. Atmospheric Environment, 35(9), 1537-1565. doi:10.1016/S1352-2310(00)00551-3.
Dillman, D.A. (2000). Mail and internet surveys: the tailored design method. New York: John Wiley & Sons.
Donfouet, H., Cook, J., & Jeanty, P.W. (2013). The economic value of improved air quality in urban Africa: results from Douala, Cameroon. Environment and Development Economics, 20(5), 630-649. doi:10.1017/S1355770X14000552.
Dziegielewska, D., & Mendelsohn, R. (2005). Valuing air quality in Poland. Journal of Environmental and Resources Economics, 30(2), 131-163. doi:10.1007/s10640-004-1515-2.
Fabian, H.G., & Vergel, K.N. (2002). Analysis of air pollution exposure of individuals in the road environment. Journal of the Eastern Asia Society for Transportation Studies, 4(5), 55-70.
Fazal, S. (2006). Addressing congestion and transport-related air pollution in Saharanpur, India. Environment and Urbanization, 18(1), 141-154.
Firoozzarea, A., & Ghorbani, M. (2011). Investigation of citizens’ WTP for Mashhad air pollution reduction: applying Heckit model. 5th Symposium on Advances in Science & Technology, Mashhad, Iran. Retrieved Jun, 15, 2015, from http://profdoc.um.ac.ir/articles/a/1022664.pdf
Fonta, M., Ichoku, H.E., & Nwosu, E. (2010). Contingent valuation in community-based project planning: the case of Lake Bamendjim fishery restocking in Cameroon. African Economic Research Consortium, Nairobi, Research Paper 210. Retrieved Jun, 15, 2015, from https://www.africaportal.org/dspace/articles/contingent-valuation-community-based-project-planning-case-lake-bamendjim-fishery
Foster, V., & Mourato, S. (2003). Elicitation format and sensitivity to scope do contingent valuation and choice experiments give the same results? Environmental and Resource Economics, 24(2), 141-160. doi:10.1023/A:1022856329552.
Freeman, A.M. (1993). The measurement of environmental and resource values: theory and methods. Washington: Resources for the Future.
Gwilliam, K. (2003). Urban transport in developing countries. Transport Reviews, 23(2), 197-216. doi: 10.1080/01441640309893.
Gwilliam, K., Kojima, M., & Johnson, T. (2004). Reducing air pollution from urban transport. Washington, DC: World Bank.
Haab, T.C., & McConnell, K.E. (2002). Valuing Environmental and Natural Resources: the Econometrics of Non-market Valuation. Cheltenham, UK: Edward Elgar.
Hanley, N., Kriström, B., & Shogren, J.F. (2009). Coherent arbitrariness: on value uncertainty for environmental goods. Land Economics, 85(1), 41–50. doi:10.3368/le.85.1.41.
Kinney, P.L., Gatari, M., Volavka-Close, N., Ngo, N., Ndiba, P.K., Law, A., Gachanja, A., Gaita, M.S., Chilrud, S.N., & Sclar, E. (2011). Traffic impacts on PM 2. 5 air quality in Nairobi, Kenya. Environmental Science and Policy, 14(4), 369-378. doi:10.1016/j.envsci.2011.02.005.
Klose, T. (1999). The contingent valuation method in health care. Health Policy, 47(2), 97-123.
Lilley, L.C. (2000). A new approach to emissions inventory modelling - Assessing fuel and vehicle impacts on air quality. Advances in Air Pollution, 8, 389-398. doi:10.2495/AIR000391.
Loomis, J., & Ekstrand, E. (1998). Alternative approaches for incorporating respondent uncertainty when estimating willingness to pay: The case of the Mexican spotted owl. Ecological Economics, 27(1), 29-41. doi:10.1016/S0921-8009(97)00126-2.
Mendelsohn, R., & Olmstead, S. (2009). The Economic valuation of environmental amenities and disamenities: methods and applications. Annual Review of Environment and Resources, 34, 325-347. doi:10.1146/annurev-environ-011509-135201.
Mitchell, R., & Carson, R. (1993). Using surveys to value public goods: the contingent valuation method. Washington, DC: Resources for the Future.
Mitchell, R.C., & Carson R.T. (1989). Using surveys to value public goods: the contingent valuation method. Baltimore: Johns Hopkins University Press.
Morrison, M.D., Blamey, R.K., & Bennett, J.W. (2000). Minimizing payment vehicle bias in contingent valuation studies. Environmental and Resource Economies, 16(4), 407-422. doi:10.1023/A:1008368611972.
Mulaku, G.C., & Kariuki, L.W. (2001). Mapping and analysis of air pollution in Nairobi, Kenya. International Conference on Spatial Information for Sustainable Development. Nairobi, Kenya. Retrieved Jun, 15, 2015, from https://www.fig.net/resources/proceedings/2001/nairobi/mulaku-kariuki-TS3-2.pdf
Odhiambo, G.O., Kinyua, A.M., Gatebe, C.K., & Awange, J. (2010). Motor vehicles air pollution in Nairobi, Kenya. Research Journal of Environmental and Earth Sciences, 2(4), 178-187.
Omwenga, M. (2011). Integrated transport system for liveable city environment: a case study of Nairobi Kenya. 47th ISOCARP Congress. Retrieved Jun, 15, 2015, from http://www.isocarp.net/data/case_studies/2022.pdf
Ryan, M., Scott, D.A., & Donaldson, C. (2004). Valuing health care using willingness to pay: a comparison of the payment card and dichotomous choice methods. Journal of Health Economics, 23(2), 237-258. doi:10.1016/j.jhealeco.2003.09.003
Sayadi, S., Gonzalez-Roa, M.C., & Calatrava-Requena, J. (2009). Public preferences for landscape features: the case of agricultural landscape in mountainous Mediterranean areas. Land Use Policy, 26(2), 334-344. doi:10.1016/j.landusepol.2008.04.003.
Strazzera, E., Genius, M., Scarpa, R., & Hutchinson, G. (2003). The effect of protest votes on the estimates of WTP for use values of recreational sites. Environmental and Resource Economics, 25(4), 461-476. doi:10.1023/A:1025098431440.
Venkatachalam, L. (2004). The contingent valuation method: a review. Environmental Impact Assessment Review, 24(1), 89-124. doi:10.1016/S0195-9255(03)00138-0.
Vliet, E.D.S., & Kinney, P.L. (2007). Impacts of roadway emissions on urban particulate matter concentrations in sub-Saharan Africa: new evidence from Nairobi, Kenya. Environmental Research Letters, 2(4), 1-6. doi:10.1088/1748-9326/2/4/045028.
Wang, H., & Whittington, D. (2000). Willingness to pay for air quality improvement in Sofia, Bulgaria. World Bank Policy Research Working Paper No 2280. Washington, DC: World Bank.
Wang, H., & Whittington, D. (2005). Measuring individuals’ valuation distributions using a stochastic payment card approach. Ecological Economics, 55(2), 143-154. doi:10.1016/j.ecolecon.2004.11.011.
Wang, X.J., Zhang, W., Li, Y., Yang, K.Z., & Bai, M. (2006). Air quality improvement estimation and assessment using contingent valuation method: a case study in Beijing. Environmental Monitoring and Assessment, 120(1), 153-168. doi:10.1007/s10661-005-9054-z.
Welsh, M.P., & Poe, G.L. (1998). Elicitation effects in contingent valuation: comparisons to a multiple bounded discrete choice approach. Journal of Environmental Economics and Management, 36(2), 170-85. doi:10.1006/jeem.1998.1043.
White, P.C.L., Bennett, A.C., & Hayes, E.J.V. (2001). The use of willingness-to-pay approaches in mammal conservation. Mammal Review, 31(2), 151-167. doi:10.1046/j.1365-2907.2001.00083.x.
Whitehead, J., Blomquist, G., Ready, R., & Huang, J. (1998). Construct validity of dichotomous choice contingent valuation questions. Environmental and Resource Economics, 11(1), 107-116. doi:10.1023/A:1008231430184.
WHO. (2006). Air Quality Guidelines: Global Update 2005. Geneva: World Health Organization. Retrieved Jun, 15, 2015, from http://www.who.int/phe/health_topics/outdoorair/outdoorair_aqg/en/
