PENDEKATAN METODE LANGSUNG DAN METODE TIDAK LANGSUNG UNTUK MENENTUKAN MANFAAT PENINGKATAN KUALITAS UDARA DI JAKARTA: STUDI KASUS DI JAKARTA TIMUR Tesis Magister Oleh iauaty Dollri s R NIM.25395021
BIDANG KHUSUS TEKNOLOGI PENGELOLAAN LINGKUNGAN PROGRAM STUDI TEKNIK LINGKUNGAN FAKULTAS PASCASARJANA INSTITUT TEKNOLOGI BANDUNG 1999
ABSTRAK
Berdasarkan hasil pemantauan kualitas udara di Jakarta tahun 1997, kadar TSP rata-rata harian telah mendekati ambang batas Baku Mutu udara ambien. Lima puluh lima prosen (55%) dari kandungan TSP tersebut merupakan partikulat berukuran dibawah 10 mikron atau PM,o yang memberikan dampak negatif terhadap kesehatan, yaitu mortalitas dan morbiditas. Kerugian yang diakibatkan oleh PM I o (mortalitas dan morbiditas) diperkirakan mencapai Rp. 725 juta per tahun pada tahun 1996 (Bank Dunia). Metode yang digunakan oleh Bank Dunia dalam memperkirakan angka kerugian tersebut adalah metode dosis-respons dengan mengacu pada standar negara Amerika yang disesuaikan dengan kondisi di Indonesia.
Didorong oleh keinginan untuk membandingkan hasil penelitian yang dilakukan oleh Bank Dunia tersebut dan memberikan masukan kepada penentu kebijakan pengendalian pencemaran udara, dilakukan penelitian untuk menentukan kesanggupan membayar masyarakat atau willingness-to-pay (WTP) bagi suatu peningkatan kualitas udara di Jakarta dengan menggunakan metode langsung dan metode tidak langsung. Dengan diketahuinya WTP setiap rumah tangga, nilai manfaat peningkatan kualitas udara pun dapat dihitung.
Metode langsung, yaitu contingent valuation method (CVM), menentukan nilai suatu benda publik (kualitas udara) secara eksplisit dari ungkapan individu tentang harga kualitas udara di pasar hipotetis. Harga kualitas udara diketahui dengan cara menanyakan langsung kepada individu tentang kesanggupannya membayar. Metode tidak langsung, yaitu model fungsi utilitas tak langsung, menentukan nilai kualitas udara secara implisit dari kebutuhan akan barang konsumsi yang diasosiasikan dengan kualitas udara. Barang konsumsi tersebut adalah rumah dan perawatan/pengobatan untuk kesehatan.
Pengumpulan data primer dilakukan melalui survei rumah tangga di Kelurahan Jati, Kecamatan Pulogadung, Jakarta Timur. Pengambilan sampel bersifat acak terstratifikasi dengan jumlah sampel 1000 rumah tangga yang dibagi atas 3 tingkat sosio ekonomi berdasarkan pengeluaran per kapita per bulan. Wawancara dilakukan terhadap kepala rumah tangga dengan mengajukan sejumlah pertanyaan yang terstruktur termasuk pertanyaan WTP.
Data diolah secara statistik deskriptif dan pemodelan fungsi utilitas translog. WTP yang diperoleh dari kedua metode tersebut dibandingkan. WTP rata-rata untuk peningkatan kualitas udara sebesar 25% dan 50% dengan menggunakan metode langsung adalah Rp. 21.293 dan Rp. 31.938 per tahun. Sedangkan WTP rata-rata yang diperoleh dengan menggunakan metode tidak langsung (model fungsi utilitas tak langsung) adalah Rp. 11.045 dan Rp. 21.463 per tahun untuk peningkatan kualitas 25% dan 50%.
Faktor-faktor yang berpengaruh terhadap nilai WTP (metode langsung ) dalam penelitian ini adalah penghasilan rumah tangga, luas tanah dan bangunan , lama tinggal , penyakit responden, status pekerjaan responden, tingkat pendidikan , kunjungan ke dokter/unit pengobatan . Bagi para pengambil keputusan, diharapkan hasil penelitian ini yang merupakan bagian dari analisa biaya-manfaat dapat digunakan sebagai alat untuk menganalisa kebijakan dan strategi agar pengendalian pencemaran udara efektif dan efisien .
ABSTRACT
Air pollution is known to cause damages to health and environment. The current air quality monitoring in Jakarta indicated that the total suspended particulates (TSP ) had reached the ambient standard limit for TSP. Fifty-five percent of TSP is estimated to be present as PM 10, which is apparently the most harmful part in TSP causing mortality and morbidity. The World Bank in its report estimated economic losses due to mortality and morbidity caused by PM 10 at Rp . 725 million per year in 1996. The method used in calculating the losses was a dose-response function adapted from the USA standard and adjusted to fit the Indonesia's condition. This study is intended to obtain people's willingness-to-pay ( WTP) for an improvement of air quality in Jakarta and calculate the health benefits resulted from 25% and 50% pollution reduction. The results were then compared to the figures estimated in the World Bank report The study is also intended to provide input to policy decision-makers in setting up strategies for a cost-effective air pollution control in Jakarta. Two methods were used to determine WTPs for 25% and 50% increase in air quality, i.e. direct method (contingent valuation) and indirect method (indirect utility function).
Direct method values public goods (air quality) explicitly from individual expressions about the price of air quality in a hypothetical market. The price of air quality is revealed by asking individual about his or her willingness to pay for an improvement of air quality. Meanwhile, indirect method calculates the price of air quality from demand function of market goods related to air quality. In this study, the demand function is developed from 2 market goods, i.e. housing services and medical services. It is assumed that air quality affects housing prices, as well as expenditures on preventive and medical care associated with the effect of pollution on health. Primary data was collected from a household survey in Kelurahan Jati , Kecamatan Pulogadung, East Jakarta involving 1000 samples, which were classified into 3 socioeconomic groups based on expenditures per capita per month. Heads of household were interviewed. The overall response rate was 96%, 4% refused to be interviewed. Following the survey, data was analyzed using descriptive statistics and translog utility function model. The results of direct method demonstrated that people's willingness-to-pay for 25% and 50% improvement in air quality were Rp.21,293 and Rp.31,938 per year respectively. While using the utility function model, WTP for 25% and 50% improvement in air quality were found to be Rp . 11,045 and Rp.21,463 per year respectively.
From the test of hypothesis for two WTPs , it was concluded that the difference between two WTPs was significant at both 95% and 99,9% confidence levels. The difference between these two WTPs was mostly caused by the following: ■
The annual land and building tax rates, which was used to represent housing prices were found to be not consistent. For example, the tax rate per m 2 of land for houses with similar quality and size in the same area (or same environmental quality) was not the same. This had resulted in inaccuracy of demand function for housing services.
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Medical service prices imputed in the indirect utility function were merely rough figures for all illnesses combined. Therefore, the model required control variables, which included health attributes of the respondents or the other household members that were associated with air pollution. However, these control variables were unable to fit into the model since it resulted in negative sum of squares.
Although there was difference between the two WTPs, for approximation the two methods could be used.
The annual benefits from air pollution reduction in Jakarta were estimated at Rp . 26 billion for 25% pollution reduction and Rp . 58.5 billion for 50% reduction. Compare these figures to the World Bank estimates of Rp . 124 billion and Rp . 254 billion.
The study also revealed factors that affected people's WTP . They included household income, land and housing sizes, living duration, respondent's illnesses, employment status, education, and visit to doctor/medical unit.
It is expected that this study - as part of cost-benefit analysis - will eventually provide input to policy decision-makers in establishing cost-effective air pollution control strategies.
