cover
Contact Name
Hasih Pratiwi
Contact Email
hpratiwi@mipa.uns.ac.id
Phone
+6282134673512
Journal Mail Official
ijas@mipa.uns.ac.id
Editorial Address
Study Program of Statistics, Universitas Sebelas Maret, Surakarta 57126, Indonesia
Location
Kota surakarta,
Jawa tengah
INDONESIA
Indonesian Journal of Applied Statistics
ISSN : -     EISSN : 2621086X     DOI : https://doi.org/10.13057/ijas
Indonesian Journal of Applied Statistics (IJAS) is a journal published by Study Program of Statistics, Universitas Sebelas Maret, Surakarta, Indonesia. This journal is published twice every year, in May and November. The editors receive scientific papers on the results of research, scientific studies, and problem solving research using statistical method. Received papers will be reviewed to assess the substance of the material feasibility and technical writing.
Articles 64 Documents
Forecasting Clove Price in South, Central, and North Sulawesi Using Generalized Space Time Autoregressive and Vector Autoregressive Elly Pusporani; M. Fariz Fadillah Mardianto; Nike Meliana Rahmawati; Anggita Nariswari; Firqa Aqila Hizbullah
Indonesian Journal of Applied Statistics Vol 9, No 1 (2026)
Publisher : Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.13057/ijas.v9i1.112470

Abstract

Cloves are a strategic plantation commodity in Indonesia with important economic and cultural value, and their price volatility directly affects farmers’ welfare, supply chain stability, and regional economic planning. Although previous studies have shown that the generalized space time autoregressive (GSTAR) model is more flexible than the space time autoregressive (STAR) model for heterogeneous locations, empirical studies comparing GSTAR and vector autoregressive (VAR) models for clove price forecasting across geographically interconnected provinces remain limited. This study addresses that gap by comparing the forecasting performance of GSTAR and VAR for monthly clove prices in North Sulawesi, Central Sulawesi, and South Sulawesi. The novelty of this study lies in the application of GSTAR with three spatial weighting schemes uniform, inverse distance, and cross-correlation normalization and its comparison with VAR in the context of clove price forecasting. Monthly data from January 2015 to December 2024 obtained from the Central Statistics Agency were analyzed using an 80:20 training-testing split. Stationarity testing showed that all series became stationary after first differencing, and lag selection based on the Akaike information criterion identified lag 1 as optimal for both models. The results indicate that the GSTAR(1)I(1) model with cross-correlation normalization weights provides the best forecasting performance, with an average MAPE of 3.18% and RMSE of 5,729.84, outperforming the VARI(1,1) model, which produced an average MAPE of 10.57% and RMSE of 15,214.11. These findings confirm that incorporating spatial dependence significantly improves forecasting accuracy and demonstrates that GSTAR is a more effective model for geographically interconnected commodity markets.Keywords: Love price, forecast, GSTAR, SDGs 8, decent work and economic growth, VAR.
Gold Price Forecasting with Long Short Term Memory (LSTM) and ARIMAX Method Raisa Naura Adila; Abdurakhman Abdurakhman
Indonesian Journal of Applied Statistics Vol 8, No 2 (2025)
Publisher : Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.13057/ijas.v8i2.97739

Abstract

Gold is very popular investment instrument due to its annual prices increases. In the long term, gold prices follow a nonlinear pattern, but in the short term, there are fluctuations influenced by various factors, including global market dynamics, monetary policy, and overall economic conditions. Therefore, predicting gold prices is an important step in minimizing risk and maximizing profits for investors. In this study, we analyze the performance of two methods for forecasting global gold prices, namely long short term memory (LSTM) and autoregressive integrated moving average with exogenous variables (ARIMAX). Data used is weekly global gold price data from August 1, 2000, to June 1, 2024. The variables used are Close as the dependent variable and Open as the exogenous variable. The data used is stationary data through the differencing process and algorithmic transformation to overcome non-stationarity issues. The best LSTM model uses the Tanh activation function with 30 LSTM units, 10 timesteps, and a dropout of 0.01, resulting in a MAPE value of 5.323%. The best ARIMAX model obtained was the ARIMAX (0,1,1) model, with a MAPE value of 0.55% for the test data and 0.61% for the training data. The research results, indicate that the higher accuracy of ARIMAX reflects its suitability for linear data such as gold prices, but the accuracy of LSTM which is below 10% still performs well for more complex data patterns.Keywords: gold price; forecasting; LSTM; arimax.
Pemodelan Efek Transmisi Inflasi Minyak Goreng di Jawa Barat, Jawa Tengah, dan Jawa Timur dengan Pendekatan BEKK GARCH M. Hafidz Habibullah
Indonesian Journal of Applied Statistics Vol 9, No 1 (2026)
Publisher : Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.13057/ijas.v9i1.100076

Abstract

Konsumsi minyak goreng di Indonesia menunjukkan kecenderungan meningkat dan berfluktuasi setiap tahunnya. Selain faktor internal, volatilitas inflasi minyak goreng juga dapat dipengaruhi oleh spillover effect dari wilayah lain. Dengan mengasumsikan adanya heteroskedastisitas pada model rata-rata, model Baba, Engel, Kroner-generalized auto regressive conditional heteroscedasticity (BEKK-GARCH) cocok digunakan untuk menganalisis volatilitas spillover effect dari inflasi minyak goreng di Jawa Barat, Jawa Tengah, dan Jawa Timur. Efek transmisi berita, yang ditandai dengan transmisi dua arah, terjadi dari inflasi minyak goreng di Jawa Barat ke Jawa Timur dan dari Jawa Tengah ke Jawa Timur, sedangkan transmisi satu arah diamati dari Jawa Timur ke Jawa Tengah. Untuk spillover effect , yang ditandai dengan transmisi volatilitas dua arah, terjadi antara Jawa Barat dan Jawa Timur, serta dari Jawa Tengah ke Jawa Timur, sementara transmisi satu arah terjadi dari Jawa Tengah ke Jawa Barat. Oleh karena itu, pengendalian inflasi harus difokuskan pada wilayah dengan tingkat konsumsi tertinggi.Cooking oil consumption in Indonesia shows a tendency to increase and fluctuate annually. Besides internal factors, the volatility of cooking oil inflation can also be influenced by spillover effects from other regions. Assuming heteroscedasticity in the average model, the Baba, Engel, Kroner-generalized auto regressive conditional heteroscedasticity (BEKK-GARCH) model is suitable for analyzing the volatility spillover effect of cooking oil inflation in West Java, Central Java, and East Java. The news transmission effect, marked by two-way transmission, occurs from cooking oil inflation in West Java to East Java and from Central Java to East Java, while one-way transmission is observed from East Java to Central Java. For the spillover effect, characterized by two-way volatility transmission, it takes place between West Java and East Java, as well as from Central Java to East Java, while one-way transmission occurs from Central Java to West Java. Consequently, controlling inflation should focus on regions with the highest consumption levels.Kata kunci: Inflasi minyak goreng, spillover effect, BEKK-GARCH.Keywords: Cooking oil inflation, spillover effect, BEKK-GARCH.
Analisis Unmet Need Pelayanan Kesehatan pada Lansia di Indonesia dengan Regresi Logistik Biner Tiga Level Iftina Ika Rahmawati; Christiana Anggraeni Putri
Indonesian Journal of Applied Statistics Vol 9, No 1 (2026)
Publisher : Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.13057/ijas.v9i1.110631

Abstract

Indonesia memasuki masa ageing population dengan tantangan yang muncul akibat populasi semakin menua. Lansia merupakan kelompok yang rentan dalam hal kesehatan, tetapi di tahun 2024 unmet need pelayanan kesehatan pada lansia masih cukup tinggi dan selama sepuluh tahun terakhir tidak mengalami penurunan yang signifikan. Penelitian ini bertujuan untuk menganalisis variabel-variabel yang memengaruhi unmet need pelayanan kesehatan pada lansia di Indonesia tahun 2024 berdasarkan karakteristik individu dan kontekstual. Data yang digunakan meliputi Survei Sosial Ekonomi Nasional Maret, Potensi Desa, dan publikasi Badan Pusat Statistik. Metode analisis yang digunakan adalah regresi logistik biner tiga level dengan random intercept. Hasil analisis menunjukkan unmet need lebih banyak terjadi pada lansia tua dengan tingkat pendidikan tidak bersekolah, masih bekerja, merokok, tidak memiliki jaminan kesehatan, serta tidak ada caregiver. Variabel usia kategori lansia tua, tingkat pendidikan kategori tidak sekolah, status bekerja, status merokok, kepemilikan jaminan kesehatan, pengeluaran, keberadaan caregiver, persentase penduduk miskin, rasio fasilitas kesehatan, rasio dokter, serta rasio anggaran belanja fungsi kesehatan berpengaruh signifikan terhadap status unmet need pelayanan kesehatan pada lansia. Nilai random intercept yang signifikan menunjukkan adanya perbedaan antar rumah tangga (ICC= 0,1560) dan antar kabupaten/kota (ICC= 0,1042) dalam peluang terjadinya unmet need pelayanan kesehatan. Nilai tersebut mengindikasikan bahwa sebesar 15,60% dan 10,42% dari total varians unmet need pelayanan kesehatan disebabkan oleh faktor tingkat rumah tangga dan kabupaten/kota. Indonesia is moving toward an ageing population phase, accompanied by challenges arising from an increasingly older demographic. Older adults are a vulnerable group in terms of health; however, in 2024, the proportion of unmet healthcare needs among this group remains relatively high and has not shown a significant decline over the past decade. This study aims to analyze the factors associated with unmet healthcare needs among older adults in Indonesia in 2024 based on individual and contextual characteristics. The data used were drawn from the March National Socioeconomic Survey (Susenas), the Village Potential Survey (Podes), and publications by Statistics Indonesia (Badan Pusat Statistik). A three-level binary logistic regression model with a random intercept was applied. The results show that unmet healthcare needs are more prevalent among older adults of advanced age, those with no formal education, those who are still working, smokers, individuals without health insurance, and those without caregivers. Significant factors include age, education level, employment status, smoking status, health insurance ownership, expenditure, presence of a caregiver, poverty rate, health facility ratio, physician ratio, and health expenditure ratio. The significant random intercept indicates that differences exist between households (ICC = 0.1560) and regions (ICC = 0.1042) in the likelihood of experiencing unmet healthcare needs. These values suggest that 15.60% and 10.42% of the total variance in unmet healthcare needs are attributable to household-level and region-level factors, respectively.Kata Kunci: Lansia, unmet need pelayanan kesehatan, regresi logistik biner tiga level.Keywords: Older adult, unmet need for health services, three level binary logistic regression.