Judul: Financial Feasibility Analysis of Rubber and Oil Palm Farming in Dolok Masihul District, Serdang Bedagai Regency, North Sumatera Province
Abstrak: Upaya Kabupaten Serdang Bedagai dalam meningkatkan luas lahan kelapa sawit memiliki persaingan dengan komoditas karet. Tanaman karet merupakan tanaman yang diusahakan secara turun temurun. Petani tidak memiliki catatan history tentang usahatani karet dan kelapa sawit sehingga tidak diketahui secara pasti manakah usahatani yang lebih layak untuk dijalankan. Penelitian ini bertujuan untuk (1) Mengidentifikasi aspek-aspek kelayakan dan mengestimasi kelayakan finansial usahatani karet dan kelapa sawit di Kecamatan Dolok Masihul (2) Menganalisis switching value dan sensitivitas perubahan harga jual output dan harga beli input pada usahatani karet dan kelapa sawit di Kecamatan Dolok Masihul dan (3) Menganalisis persepsi petani terhadap usahatani karet dan kelapa sawit di Kecamatan Dolok Masihul. Metode dalam penelitian ini adalah analisis deskriptif, analisis kelayakan finansial, analisis switching value, analisis sensitivitas dan analisis likert. Hasil penelitian menunjukkan usahatani karet dan kelapa sawit layak untuk dijalankan. Berdasarkan kriteria investasi menunjukkan usahatani kelapa sawit lebih menguntungkan dibandingkan dengan usahatani karet. Analisis switching value dan sensitivitas menunjukkan bahwa adanya perubahan harga output dan input mempengaruhi pendapatan petani karet dan kelapa sawit. Alasan yang mempengaruhi petani untuk tetap berusahatani karet antara lain usahatani karet adalah usahatani yang dilakukan secara turun temurun, pendapatan usahatani karet masih dapat memenuhi kebutuhan hidup sehari-hari, dan petani nyaman dalam berusahatani karet., The efforts of Serdang Bedagai Regency in increasing the area of oil palm land have competition with rubber commodities. Rubber plant is a plant that is cultivated from generation to generation. Farmers do not have historical records of rubber and oil palm farming so it is not known for sure which farming is more feasible to run. This study aims to (1) Identify the feasibility aspects and estimate the financial feasibility of rubber and oil palm farming in Dolok Masihul District (2) Analyze the switching value and the sensitivity of changes in the selling prices of output and the purchase price of inputs on rubber and oil palm farming in Dolok Masihul District and (3) Analyze farmers’ perceptions of rubber and oil palm farming in Dolok Masihul District. The methods in this research are descriptive analysis, financial feasibility analysis, switching value analysis, sensitivity analysis and likert analysis. The result showed that rubber and oil palm farming was feasible 94 to run. Based on the investment criteria, it shows that oil palm farming is more profitable than rubber farming. Switching value analysis and sensitivity analysis shows that changes in output and input prices affect the income of rubber and oil palm farmers. The reasons that influence farmers to continue farming rubber are: rubber farming has been carried out from generation to generation, rubber farming income can still meet the needs of daily life, and farmers are comfortable in rubber farming.
Keyword: welfare, conversion, cultivation, production, profit

Judul: Economic and Risk Analysis of Plant Conversion of Rubber to Oil Palm Plantation in Pemayung District Batang Hari Regency Jambi
Abstrak: Rubber is a strategic commodity in almost all of regencies in the province of Jambi and has become a part of culture of Jambi community. For a plant that has become a superior commodity and has been rooted in the community, the government of Jambi province continues expanding and maintaining Rubber cultivation area. However, lately many companies and rubber farmers in Jambi Province converted their rubber crop into oil palm crop as it is considered more profitable economically. The Background of the decline of the interest of the farmers to the rubber crop is caused by the fluctuating prices and low productivity of the rubber, a large amount of rubber plants that are old, damaged and unproductive, the usage of non superior clone seedlings as well as the conditions of the rubber plantation that resembles forest. These conditions encouraged farmers to convert the rubber into oil palm plantation. Objectives of this research are: (1) to estimate the conversion rate from rubber into oil palm; (2) to evaluate whether economic benefits of oil palm is greater than that of rubber; (3) to identify some factors affecting farmers in converting their commodity; (4) to analyze the risks faced by farmers in implementing such conversion; and (5) to analyze the optimal combination of land use between rubber and oil palm based on portfolio risk theory. The research was conducted in the District Pemayung, Batang Hari Regency, Province of Jambi. The selection of the study site is purposively. The research was conducted in December 2012 to March 2013. The data used is the time series and cross section data. The type of data used in this study is primary data obtained through interviews using a questionnaire with rubber farmers and oil palm farmers who initially were rubber farmers. It is also used secondary data obtained from Batang Hari Regency Plantation Office, District Pemayung, Bappeda Batang Hari Regency, Office of Agriculture and Plantation Extension, and BPS. Research results showed the rate of conversion of rubber land in the District Pemayung Batang Hari regency, during period of 2003 to 2011, rubber plant conversion was quite high, achieving about 2,214 hectares (ha). However, there were also a program of new rubber plantation development amounting 1,903 ha in the same period. The net rubber land conversion was only 311 ha in the period of 2003 to 2011.This became evident that there has been a conversion of smallholder rubber in 2003-2011 in District of Pemayung Batang Hari. Based on feasibility analysis, including NPV, IRR, and Net B/C for rubber and oil palm during the period of 25 years, the value of NPV, IRR, and Net B/C oil palm plantation are significantly higher than those of rubber i.e., Rp 52.478.251, 19%, and 2,59 compared to Rp 105.982.309, 29%, and 4,48. Respectively these confirmed our hypothesis that oil palm is financially more beneficial than rubber. The factors that significantly affect land conversion is farmers time allocation, rubber plants damaged condition, rubber pests, and trial and error factors. Risk analysis indicated that the risk of monoculture rubber plantation is larger than that of monoculture
Keyword: rubber, oil palm, plant conversion, risk, portofolio risk

Judul: Approximation of the Median of Poisson Distribution Using the Relation of Poisson-Gamma Distribution
Abstrak: A major drawback of median is that median cannot usually be defined in closed form, even in the cases where their distribution functions are known. This study gives an approximation of the closed form for the median of the Poisson distribution by using the relation of Poisson-Gamma distribution. The approximation uses elementary techniques based on the monotonicity of certain sequences involving tail probabilities of the Poisson distribution and the Central Limit Theorem. Furthermore, a closed form expression for the mean absolute deviation 􀜧|􀜰􀰒 􀵆 􀜯􀝁􀝀􁈺􀜰􀰒􁈻| is also studied. The median is relevant because of the fact that it minimizes the mean absolute deviation of a Poisson random variable (􀜰􀰒􁈻 by considering median as central tendency.
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