Bridging the Yield Gap in Soybean Farming: Technical Efficiency and Key Determinants from a Stochastic Frontier Study in Chiang Mai Province, Thailand
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Abstract
The study aimed to analyze the technical efficiency of soybean production and identify factors influencing the technical inefficiency among soybean farmers in Chiang Mai Province. Data were collected through interviews with 100 soybean farmers across four districts in Chiang Mai: Chiang Dao, Hang Dong, Phrao, and Mae Rim. The analysis was conducted using the stochastic frontier analysis (SFA) method, employing a Cobb-Douglas production function integrated with a copula model, and was performed using the R Studio program. The findings found that farmers' average technical efficiency score in producing soybeans was 0.77, suggesting a moderate efficiency level with a 23 percent potential for improvement. The labor hours utilized in production, expenditure on fertilizers, and the quantity of soybean seeds used statistically significantly influenced soybean yield. The results further revealed that landownership and farming experiences significantly negatively impacted technical inefficiency in soybean production. In contrast, farm size exhibited a significant positive impact on technical inefficiency. Consequently, the study suggested that adjusting these factors could reduce technical inefficiency in soybean production among farmers in Chaing Mai Province.
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References
USDA. Oilseeds and products annual: Thailand; Report No. TH2025-0009. Foreign Agricultural Service, U.S. Department of Agriculture, 2025. https://apps.fas.usda.gov/newgainapi/api/Report/DownloadReportByFileName?fileName=Oilseeds%20and%20Products%20Annual_Bangkok_Thailand_TH2025-0009 (accessed Aug 16, 2022).
Office of Agricultural Economics. Situation of important agricultural products and trends in 2023; Ministry of Agriculture and Cooperatives, 2022. https://www.oae.go.th/assets/portals/1/files/jounal/2565/231225652566.pdf (accessed Jan 21, 2023). (in Thai).
Department of Agriculture. Research and development on soybean; Ministry of Agriculture and Cooperatives, 2025. https://www.doa.go.th/research/attachment.php?aid=2246 (accessed Nov 19, 2022). (in Thai).
Office of Agricultural Economics. Agricultural economic information by product in 2021; Ministry of Agriculture and Cooperatives, 2022. https://www.oae.go.th/assets/portals/1/files/jounal/2565/commodity2564.pdf (accessed Dec 14, 2023). (in Thai).
Office of Agricultural Economics. Agricultural economic information by product for the year 2022; Ministry of Agriculture and Cooperatives, 2023. https://www.oae.go.th/assets/portals/1/files/jounal/2566/commodity2565.pdf (accessed Mar 14, 2024). (in Thai).
Office of Agricultural Economics. Situation of important agricultural products and trends in 2024; Ministry of Agriculture and Cooperatives, 2023. https://www.oae.go.th/assets/portals/1/files/jounal/2566/trend2567.pdf (accessed Feb 3, 2024). (in Thai).
FAOSTAT. Crop and livestock products. Food and Agriculture Organization of the United Nations. https://www.fao.org/faostat/en/#data/QCL (accessed Mar 21, 2025). (in Thai).
Office of Agricultural Economics. Agricultural statistics of Thailand 2022; Ministry of Agriculture and Cooperatives, 2023. https://www.oae.go.th/assets/portals/1/files/jounal/2566/yearbook2565.pdf (accessed Mar 14, 2024). (in Thai).
Department of Agricultural Extension. Crop production data report; Ministry of Agriculture and Cooperatives, 2025. https://production.doae.go.th/service/data-state-location/index (accessed Jan 26, 2025). (in Thai).
Office of Agricultural Economics. Agricultural economic information by product in 2021; Ministry of Agriculture and Cooperatives, 2021. https://www.oae.go.th/assets/portals/1/files/jounal/2565/commodity2564.pdf (accessed Jan 29, 2022). (in Thai).
Sharma, P. U.; Dupare, B. U.; Patel, R. M. Technical efficiency of soybean production in Madhya Pradesh: a stochastic Frontier Approach. Soybean Research 2016, 14 (1), 68–77.
Etwire, P. M.; Martey, E.; Dogbe, W. Technical efficiency of soybean farms and its determinants in Saboba and Chereponi districts of northern Ghana: A stochastic frontier approach. Sustainable Agriculture Research 2013, 2(4), 106–116. https://doi.org/10.5539/sar.v2n4p106.
Musaba, E. C.; Banda, B. Analysis of technical efficiency of small-scale soybean farmers in Mpongwe District, Zambia: A Stochastic Frontier Analysis. Journal of Agriculture and Veterinary Science 2020, 13(12), 49–56. https://doi.org/10.9790/2380-1312024956.
Alabi, O. O.; Maharazu, I.; Aluwong, J. S.; Atteh, P. A.; Obida, A. Socioeconomic evaluation and technical efficiency of soybean (Glycine max) production in northwest Nigeria: A parametric approach. SVU-International Journal of Agricultural Sciences 2024, 6(3), 36–46. https://doi.org/10.21608/svuijas.2024.287999.1368.
Otitoju, M. A.; Arene, C. J. Constraints and determinants of technical efficiency in medium-scale soybean production in Benue State, Nigeria. Journal of Agricultural Research 2010, 5 (17), 2276–2280.
Rinaldi, J.; Arya, N. N.; Mahaputra, I. K.; Elisabeth, D. A. A.; Resiani, N. M. D.; Arsana, I. G. K. D.; Silitonga, T. F. Production factors, technical, and economic efficiency of soybean (Glycine max L. Merr.) farming in Indonesia. Open Agriculture 2023, 8 (1), 20220194. https://doi.org/10.1515/opag-2022-0194.
Puphoung, S. Technical efficiency of farmers' rice production in Chiang Rai province analysis. Prawarun Agricultural Journal 2024, 21(1), 106–117. (in Thai).
Somcom, S.; Wana, C. Technical efficiency analysis of rice production of farmers in Chai-Nat. Journal of Chandrakasemsarn 2020, 26(2), 179–196. (in Thai).
Rahman, S.; Wiboonpongse, A.; Sriboonchitta, S.; Chaovanapoonphol, Y. Production efficiency of Jasmine rice producers in Northern and North‐Eastern Thailand. Journal of Agricultural Economics 2009, 60(2), 419–435. https://doi.org/10.1111/j.1477-9552.2008.00198.x.
Sriwichai, S. Technical efficiency of farmers’ cassava production in Phayao Province. M.S. Thesis, Chiang Mai University, Chiang Mai, Thailand, 2014. (in Thai).
Krasachat, W. Technical inefficiency of chili farms in Thailand: A parametric approach. Test Engineering & Management 2020, 83, 30415–30421.
Sornin, K.; Athipanyakul, T. Production Management and Production Costs of Conventional Chili and Safer Chili of Farmers in Chaiyaphum Province. In Proceedings of the 15th Graduate Research Conference; Khon Kaen University, Thailand, 2014; pp 415–422. (in Thai).
Phummuong, J. Technical efficiency of soybean production in the rainfed area of the lower northern region, Thailand. M.S. Thesis, Chiang Mai University, Chiang Mai, Thailand, 2002. (in Thai).
Lesak, P. Technical efficiency of soybean production in irrigated zone in Chiang Mai Province by StoNED method. M.S. Thesis, Chiang Mai University, Chiang Mai, Thailand, 2013. (in Thai).
Chanaim, S.; Srichikul, W.; Mensaklo, E. A. Copula-Based Stochastic Frontier Analysis of Thai Jasmine Rice Production in the Northeast of Thailand. TEM Journal 2023, 12(4), 2312–2318. https://doi.org/10.18421/TEM124-42.
Arsad, R.; Isa, Z.; Abidin, N. H. Z.; Kamarudin, N. Measuring stock performance using stochastic frontier analysis model with dependent error approach. International Journal of Advanced and Applied Sciences 2022, 9(12), 1–10. https://doi.org/10.21833/ijaas.2022.12.001.
Chaovanapoonphol, Y.; Singvejsakul, J.; Sriboonchitta, S. Technical efficiency of Rice production in the upper north of Thailand: clustering copula-based stochastic frontier analysis. Agriculture 2022, 12(10), 1585. https://doi.org/10.3390/agriculture12101585.
Yamane, T. Statistics: An Introductory Analysis, 3rd ed.; Harper and Row: New York, 1973.
Poonkham, K. Analysis of efficiency of convention hotel in Thailand by using stochastic frontier with copula. M.S. Thesis, Chiang Mai University, Chiang Mai, Thailand, 2013. (in Thai).
Cohen, J. P. Production Functions for Medical Services. Encyclopedia of Health Economics 2014, 180–183. https://doi.org/10.1016/B978-0-12-375678-7.01010-5.
European Commission. Directorate-General for Agriculture and Rural Development – Unit A.3.: Assessment of CAP Contribution to Sustainable Productivity; European Union, 2025. https://eu-cap-network.ec.europa.eu/sites/default/files/publications/2025-04/eu-cap-network-guidelines-assessment-of-cap-contribution-annexes.pdf (accessed Aug 12, 2025).
Wiboonpongse, A.; Liu, J.; Sriboonchitta, S.; Denoeux, T. Modeling dependence between error components of the stochastic frontier model using copula: Application to intercrop coffee production in Northern Thailand. International Journal of Approximate Reasoning 2015, 65, 34–44. https://doi.org/10.1016/j.ijar.2015.04.001.
Schwarz, G. Estimating the dimension of a model. The annals of statistics 1978, 6(2), 461–464. https://doi.org/10.1214/aos/1176344136.
Burnham, K.; Anderson, D. Model selection and multi-model inference: A Practical Information-Theoretic Approach, 2nd ed.; Springer, 2004.
Aigner, D.; Lovell, C. A. K.; Schmidt, P. Formulation and estimation of stochastic frontier production function models. Journal of Econometrics 1977, 6, 21–37. https://doi.org/10.1016/0304-4076(77)90052-5.
Si, W.; Wang, X. Productivity growth, technical efficiency, and technical change in China’s soybean production. African Journal of Agricultural Research 2011, 6(25), 5606–5613. https://doi.org/10.5897/AJAR11.1080.
Thipbharos, P. Technical efficiency approach of agricultural producers by stochastic frontier analysis. Journal of Economics Chiang Mai University 2016, 20(2), 93–124. (in Thai).
Adinya, I. B.; Offem, B. O.; Ikpi, G. U. Application of a stochastic frontier production function for measurement and comparison of technical efficiency of mandarin fish and clown fish production in lowland reservoirs, ponds, and dams of Cross River State, Nigeria. The Journal of Animal & Plant Sciences 2011, 21(3), 595–600.
Butsaenkom, P. Selection of predictive variables into the multiple regression equation. Journal of Educational Measurement Mahasarakham University 2012, 17(1), 43–60. (in Thai).
Chubtong, K. Technical efficiency of pineapple production in Prachuap Khiri Khan and Chiang Rai provinces. M.S. Thesis, Chiang Mai University, Chiang Mai, Thailand, 2014. (in Thai).
Donkor, E.; Owusu, V. Effects of land tenure systems on resource-use productivity and efficiency in Ghana’s rice industry. African Journal of Agricultural and Resource Economics 2014, 9(4), 286–299. https://doi.org/10.22004/ag.econ.197016.
Omar, Z.; Fatah, F. A. Determinants of technical efficiency among coconut smallholder production in Johor, Malaysia: A Cobb-Douglas stochastic frontier production approach. IOP Conf. Series: Earth and Environmental Science 2021, 757, 012013. DOI: 10.1088/1755-1315/757/1/012013.
Ajibefun, I.; Battese, G.; Daramola, A. Determinants of technical efficiency in smallholder food crop farming: Application of stochastic frontier production function. Journal of International Agriculture 2002, 41(3), 225–240.
Sritongtae, C.; Monkham, T.; Sanitchon, J.; Lodthong, S.; Srisawangwong, S.; Chankaew, S. Identification of Superior Soybean Cultivars through the Indication of Specific Adaptabilities within Duo-Environments for Year-Round Soybean Production in Northeast Thailand. Agronomy 2021, 11(3), 585. https://doi.org/10.3390/agronomy11030585.