Judul: Analysis of Price Volatility and Vertical Integration of Cooking Oil Market in Indonesia
Abstrak: Fenomena kenaikan dan penurunan harga minyak goreng yang berbeda setiap jenisnya turut berperan sebagai penyumbang angka inflasi dalam kelompok pangan bergejolak di Indonesia. Perubahan harga yang tidak stabil tersebut menjadi tantangan tersendiri bagi produsen, pedagang besar, dan pedagang eceran. Penelitian ini bertujuan menganalisis volatilitas dan hubungan integrasi vertikal pada harga minyak goreng kemasan premium, kemasan sederhana, dan kemasan curah pada setiap tingkat harga pasar di produsen, pedagang besar, dan pedagang eceran. Penelitian ini menggunakan harga minyak goreng mingguan nasional tahun 2019-2023 diperoleh dari Pusat Informasi Harga Pangan Strategis. Analisis yang dilakukan yakni Koefisien Variasi untuk melihat fluktuasi harga, model ARCH/GARCH untuk menganalisis volatilitas, dan model VECM untuk menganalisis integrasi vertikal. Hasil penelitian menunjukkan harga minyak goreng di setiap jenis kualitas memiliki perbedaan nilai fluktuasi. Volatilitas sangat tinggi terjadi pada harga minyak goreng premium dan curah di tingkat pedagang eceran, sedangkan volatilitas tinggi terjadi pada harga minyak goreng curah di tingkat pedagang besar. Hasil VECM menunjukkan terdapat hubungan jangka panjang dan jangka pendek antar variabel harga minyak goreng pada tiga tingkat pasar berbeda., The phenomenon of increasing and decreasing cooking oil prices that are different for each type contributes to the inflation rate in the volatile food group in Indonesia. The unstable price changes are a challenge for producers, wholesalers, and retailers. This study aims to analyze the volatility and vertical integration relationship in the price of premium packaged cooking oil, simple packaging, and bulk packaging at each market price level at producers, wholesalers, and retailers. This study uses weekly national cooking oil prices for 2019-2023 obtained from the Strategic Food Price Information Center. The analysis carried out is the Coefficient of Variation to see price fluctuations, ARCH/GARCH models to analyze volatility, and VECM models to analyze vertical integration. The results show that cooking oil prices in each type of quality have different fluctuation values. Very high volatility occurs in the price of premium and bulk cooking oil at the retail level, while high volatility occurs in the price of bulk cooking oil at the wholesale level. VECM results show that there are long-run and short-run relationships between cooking oil price variables at three different market levels.
Keyword: Volatilitas, harga, integrasi, minyak goreng

Judul: Determinants of Indonesia Cooking Oil Prices (Period 2017-2022)
Abstrak: Kelangkaan minyak goreng pada awal tahun 2022 menyebabkan harga minyak goreng menjadi mahal. Penelitian ini bertujuan untuk menganalisis distribusi perdagangan dan determinan harga minyak goreng Indonesia. Metode yang digunakan dalam penelitian ini adalah analisis deskriptif dan analisis VECM dengan data bulanan 2017-2022. Hasil penelitian menunjukkan harga minyak goreng mengalami kenaikan tajam pada September 2021-April 2022. Kelangkaan minyak goreng disebabkan oleh panic buying, penimbunan, ilegal ekspor, dan gagalnya pemerintah dalam mengontrol distribusi perdagangan minyak goreng. Hasil VECM menunjukkan perubahan harga minyak goreng dalam jangka pendek dipengaruhi oleh harga minyak goreng itu sendiri, harga TBS, harga CPO dunia, produksi CPO, dan ekspor CPO. Sedangkan dalam jangka panjang dipengaruhi oleh harga TBS domestik, harga CPO dunia, produksi CPO domestik, konsumsi CPO domestik, dan ekspor CPO. Hasil IRF dan FEVD menunjukkan bahwa guncangan variabel terhadap perubahan harga minyak goreng Indonesia bervariasi antar periodenya dan memiliki persentase kontribusi yang berbeda, The scarcity of cooking oil at the beginning of 2022 caused the price of cooking oil to become expensive. This study aims to analyze the distribution of trade and the determinants of Indonesian cooking oil prices. The methods used in this study are descriptive analysis and VECM analysis with monthly data for 2017– 2022. The results showed that the price of cooking oil had experienced a sharp increase in September 2021-April 2022. The scarcity of cooking oil was caused by panic buying, hoarding, illegal exports, and the government's failure to control the distribution of cooking oil. The VECM results showed that changes in the price of cooking oil in the short term were influenced by the price of the cooking oil itself, the price of FFB, the world CPO price, CPO production, and CPO exports. Meanwhile, in the long run were affected by domestic FFB prices, world CPO prices, domestic CPO production, domestic CPO consumption, and CPO exports. The results of IRF and FEVD showed that variable shock to changes in Indonesian cooking oil prices varied between periods and had different contribution percentages.
Keyword: Cooking oil, price determinants, trade distribution

Judul: Construction of Strongly Optimal Binary Linear Code with Minimum Distance 9 and 11
Abstrak: A binary linear code of length n over q F is a subspace of n q F . A code has three parameters that attached to it, namely length, dimension, and minimum distance. A code with length n, dimension k and minimum distance d is often called [n, k, d ]-code. Usually, when two parameters are given, then we want to find a code that has the best value for the last parameter. Based on Gilbert- Varshamov bound, if a [n, k, d ]-code exists and can not be expanded, we call it a strongly optimal code. In this paper, we construct strongly optimal code with minimum distance 9 and 11. In constructing the code, we created a theorem and algorithm based on Gilbert-Varshamov bound before we implement the algorithm to MAPLE programming language. Because of computational limitations, the program can only construct up to k = 10 for d = 9 and k = 12 for d = 11.
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