Judul: Analisis Dampak Fluktuasi Harga Minyak Mentah Dunia terhadap Harga Karet Alam Domestik
Abstrak: Natural rubber is one of the leading comodity estate crop subsector in Indonesia. However, over the past few years the domestic natural rubber prices tended to fluctuate. One of the external factors that affects the price of domestic natural rubber is the price of world crude oil. The purposes of this study are to analyze the impact world crude oil prices fluctuation and other factors that effect the domestic natural rubber prices and to analyze determinant factors influencing domestic natural rubber prices. This research was analyzed with VECM using time series data from March 2008 to December 2013. The result of VECM estimation indicates that world crude oil price affects the domestic natural rubber prices in the long term. The other variables that also affect the domestic price of natural rubber in the long term are the domestic natural rubber production and inflation. The production of natural rubber gives the biggest impact in domestic natural rubber prices. Meanwhile, the world crude oil has a small effect to domestic natural rubber price.
Keyword: Bogor Agricultural University, Crude oil, Natural rubber, Time series, Vector autoregressive, Impulse response function

Judul: The Effect of Expanding the Coverage of International Tripartite Rubber Council (ITRC) on World Rubber Prices
Abstrak: Salah satu hasil perkebunan yang menjadi komoditas utama dan diekspor oleh negara Indonesia adalah karet. Namun, karet memiliki masalah yang krusial yakni fluktuasi harga karet dunia. Oleh karena itu, dibentuk sebuah forum kerjasama yang dikenal sebagai International Tripartite Rubber Council (ITRC) untuk menstabilkan harga karet. Dalam melakukan kebijakan ITRC terlihat bahwa negara anggota tidak memberikan dampak yang signifikan terhadap harga karet dunia. Penelitian ini bertujuan untuk menganalisis penambahan cakupan negara anggota ITRC dalam memperbaiki harga karet dunia dengan menggunakan ARDL dan ECM dengan periode 2013-2019. Selain itu, penelitian ini juga melihat dinamika ekspor dan harga dari negara–negara tambahan maupun negara ITRC dengan menggunakan metode deskriptif. Hasil penelitian menunjukkan bahwa penambahan negara lainnya tidak memberikan dampak yang signifikan terhadap perbaikan harga karet dunia. Hal ini dibuktikan dengan penggunaan dua model dalam memastikan bahwa hasil yang didapat benar adanya. Dan hasil yang ditunjukkan pada metode ARDL sejalan dengan hasil dari metode ECM yang berarti bahwa kebijakan pembatasan ekspor sudah tidak efektif dalam memperbaiki harga karet dunia, Rubber is one of the major agricultural commodities produced and exported by Indonesia. However, rubber faces a crucial issue of fluctuating world prices. Therefore, an international cooperation forum known as the International Tripartite Rubber Council (ITRC) was established to stabilize rubber prices. However, the policy measures implemented by the ITRC member countries do not seem to have a significant impact on world rubber prices. This research aims to analyze the impact of expanding the coverage of ITRC member countries in improving world rubber prices using the ARDL and ECM models for the period of 2013-2019. Additionally, this study examines the dynamics of exports and prices among the additional countries and the existing ITRC member countries using descriptive methods. The research findings indicate that the addition of countries does not have a significant impact on improving world rubber prices. This is supported by the use of two models to ensure the validity of the results. Both the ARDL and ECM models show consistent results, indicating that export restriction policies are no longer effective in improving world rubber prices.
Keyword: World Rubber Prices, Export Restrictions, ARDL, ECM

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.
Keyword: