Exploring the Impact of Wheat Prices and Annual Income on Pig Carcass Prices in European Countries: A Spatial Panel Regression Analysis
Abstract
1. Introduction
- (a)
- How do feed prices, specifically wheat prices, affect pork carcass prices within the EU?
- (b)
- Does the annual income of the population influence the demand and price of pork in different Member States?
- (c)
- How did these interactions evolve during the 2014–2023 period, considering external shocks such as changes in trade policies and global economic contexts?
- Due to rising production costs, higher wheat prices are positively correlated with increased pork carcass prices.
- Higher income levels lead to increased demand for pork, thereby driving up both demand and prices, although this relationship may vary by region.
- There is a spatial connection among EU countries, whereby pork carcass prices in one region influence those in neighboring regions.
Literature Review
2. Materials and Methods
2.1. Data
2.1.1. Variables
2.1.2. Time Frame
2.1.3. Sources
- Pork carcass prices: Data on pork carcass prices (measured in euros per 100 kg) were sourced from the European Commission’s Market Observatory.
- Wheat prices: Wheat price data (measured in euros per metric ton) were obtained from Eurostat.
- Annual income: Annual net earnings (measured in euros) were sourced from Eurostat.
2.2. Analysis
2.2.1. Spatial Panel Regression Model
2.2.2. Spatial Weight Matrix
2.2.3. Key Model Equations
2.2.4. Interpretation
2.2.5. Diagnostic Tests
2.3. Software and Tools
3. Results
3.1. Impact of Wheat Prices on Pork Carcass Prices
3.2. Influence of Annual Income Levels
3.3. Spatial Dependencies
4. Discussion
5. Conclusions
Author Contributions
Funding
Institutional Review Board Statement
Data Availability Statement
Conflicts of Interest
Abbreviations
| EU | EU |
| LR | Wald and likelihood ratio |
| SLX | Spatial Lag of X |
| SEM | Spatial error model |
| SAR | Spatial autoregressive |
| SDEM | Spatial Durbin error model |
| SDM | Spatial Durbin model |
| SAC | Spatial autoregressive combined |
References
- Serra, T.; Gil, J.M. Local polynomial fitting and spatial price relationships: Price transmission in EU pork markets. Eur. Rev. Agric. Econ. 2006, 33, 415–436. [Google Scholar] [CrossRef]
- Rotaru, I. Evolution of pigs’ livestock and pork production in the world. Sci. Pap. Ser. D. Anim. Sci. 2018, 61, 189–193. [Google Scholar]
- Sandu, M.; Mantea, Ș. Study on the meat sector in the EU. Sci. Pap. Ser. Manag. Econ. Eng. Agric. Rural Dev. 2017, 17, 375–380. [Google Scholar]
- Szűcs, I.; Vida, V. Global Tendencies in Pork Meat-Production, Trade and Consumption. Appl. Stud. Agribus. Commer. 2017, 11, 105–112. [Google Scholar] [CrossRef]
- Szymanska, E.J. The pork market in Poland against the background of the EU. Ann. Pol. Assoc. Agric. Agribus. Econ. 2019, XXI, 504–513. [Google Scholar] [CrossRef]
- Pindyck, R.S. Volatility and commodity price dynamics. J. Fut. Mark. 2004, 24, 1029–1047. [Google Scholar] [CrossRef]
- Assefa, T.T.; Meuwissen, M.P.; Oude Lansink, A.G. Price risk perceptions and management strategies in selected European food supply chains: An exploratory approach. NJAS Wagening. J. Life Sci. 2018, 80, 15–26. [Google Scholar] [CrossRef]
- Manioudis, M.; Meramveliotakis, G. Broad strokes towards a grand theory in the analysis of sustainable development: A return to the classical political economy. New Political Econ. 2022, 27, 866–878. [Google Scholar] [CrossRef]
- Klarin, T. The Concept of Sustainable Development: From its Beginning to the Contemporary Issues. Zagreb International Review of Economics and Business. Sciendo 2018, 21, 67–94. [Google Scholar] [CrossRef]
- Istudor, N.; Dinu, V.; Gogu, E.; Prada, E.M.; Petrescu, I.M. Impact of Education and Economic Growth on Labour Migration in the European Union. A Panel Data Analysis. EM Econ. Manag. 2020, 23, 55–67. [Google Scholar] [CrossRef]
- Dinu, V.; Dragoş, C.M.; Mare, C.; Dragoş, S.L.; Mare, R. Economic and institutional determinants of environmental health and sustainability: Spatial and nonlinear effects for a panel of worldwide countries. Oeconomia Copernic. 2024, 15, 195–227. [Google Scholar] [CrossRef]
- Tluczak, A. The forecast of the pig meat prices in the EU—The use of adaptive winters’s model. Sci. Pap. Ser. Manag. Econ. Eng. Agric. Rural Dev. 2016, 16, 307–311. [Google Scholar]
- Adesehinwa, A.O.K.; Makinde, G.E.O.; Oladele, O.I. Socio economic characteristics of pig farmers as determinant of pig feeding pattern in Oyo State, Nigeria. Livest. Res. Rural Dev. 2003, 15, 98–106. [Google Scholar]
- Babovic, J.; Caric, M.; Djordjevic, D.; Lazic, S. Factors influencing the economics of the pork meat production. Agric. Econ. 2011, 57, 203–209. [Google Scholar] [CrossRef]
- Soare, E.; Chiurciu, I.A. Study on the pork market worldwide. Sci. Pap. Ser. Manag. Econ. Eng. Agric. Rural Dev. 2017, 17, 321–326. [Google Scholar]
- Jeremic, M.; Lovre, K.; Matkovski, B. Serbian pork market analysis. Econ. Agric. 2018, 65, 1449–1460. [Google Scholar] [CrossRef]
- Bielik, P.; Šajbidrova, Z. Elasticity of consumer demand on pork meat in the Slovak Republic. Agric. Econ. 2009, 55, 2–19. [Google Scholar] [CrossRef]
- Jabbar, M.A.; Akter, S. Market and other factors affecting farm specific production efficiency in pig production in Vietnam. J. Int. Food Agribus. Mark. 2008, 20, 29–53. [Google Scholar] [CrossRef]
- Lâm, Đ.T.; Cường, T.T.; Huyền, N.T.; Xuân, V.K.; Đức, N.A. Analysis of factors affecting demand for pork consumption in Vinh City, Nghe an Province. J. Sci. Dev. 2013, 11, 429–438. [Google Scholar]
- Ajala, M.K. Analysis of factors affecting the management of pigs in Kaduna State, Nigeria. Agric. J. 2007, 2, 343–347. [Google Scholar]
- Adetunji, M.O.; Adeyemo, K.E. Economic efficiency of pig production in Oyo State, Nigeria: A stochastic production frontier approach. Am. J. 2012, 2, 382–394. [Google Scholar] [CrossRef]
- Young, M. Efficiency of Pork Production: A USA, Canada, and Ireland comparison. In Proceedings of the Allen D. Leman Swine Conference; The University of Minnesota: Minneapolis, MN, USA, 2005; 124p. [Google Scholar]
- Mcewan, K.; Marchand, L.; Shang, Z. The Canadian pork industry and COVID-19: A year of resilience. Can. J. Agric. Econ. 2021, 69, 225–232. [Google Scholar] [CrossRef]
- Montariol, C. Economy and prospects of the pig sector in France and EU. Inst. Natl. De La Rech. Agron. 2003, 16, 341–348. [Google Scholar]
- Havlícek, J.; Dömeová, L.; Smutka, L.; Rezbová, H.; Severová, L.; Šubrt, T.; Šrédl, K.; Svoboda, R. Efficiency of Pig Production inthe Czech Republic and in an International Context. Agriculture 2020, 10, 597. [Google Scholar] [CrossRef]
- Pechrová, M.S.; Medonos, T. Czech Pig Farming Sector after the Entrance to the EU. In Proceedings of the International Conference on European Integration, Ostrava, Czech Republic, 19–20 May 2016. [Google Scholar]
- Bellini, S. The pig sector in the EU. In Understanding and Combatting African Swine Fever; Wageningen Academic: Wageningen, The Netherlands, 2021. [Google Scholar] [CrossRef]
- Utnik-Banaś, K.; Schwarz, T.; Szymańska, E.; Bartlewski, P.; Satoła, Ł. Scrutinizing pork price volatility in the EU over the last decade. Animals 2022, 12, 100. [Google Scholar] [CrossRef]
- Predanócyová, K.; Kubicová, L.; Kádeková, Z.; Košičiarová, I. Pork Meat and Meat Products Market in the Slovak Republic; Slovak University of Agriculture in Nitra: Nitra, Slovakia, 2022; ISBN 978-80-552-2507-4. [Google Scholar] [CrossRef]
- Wu, L.; Gong, X.; Qin, S.; Chen, X.; Zhu, D.; Hu, W.; Li, Q. Consumer preferences for pork attributes related to traceability, information certification, and origin labeling: Based on China’s Jiangsu Province. Agribusiness 2017, 33, 424–442. [Google Scholar] [CrossRef]
- Stupnišek, I.; Željka, M. Analysis of the world and Croatian pork market. Agron. Glas. Glas. Hrvat. Agron. Društva 2019, 81, 17–34. [Google Scholar]
- Liao, T.; Gan, M.; Zhu, Y.; Lei, Y.; Yang, Y.; Zheng, Q.; Niu, L.; Zhao, Y.; Chen, L.; Wu, Y.; et al. Carcass and Meat Quality Characteristics and Changes of Lean and Fat Pigs After the Growth Turning Point. Foods 2025, 14, 2719. [Google Scholar] [CrossRef] [PubMed]
- Sońta, M.; Rekiel, A.; Więcek, J.; Zalewska, A. Pig welfare and productivity in selected alternative systems. A niche market for pork. Ann. Anim. Sci. 2025. [Google Scholar] [CrossRef]
- Ornelas Herrera, S.I.; Baba, Y.; Kallas, Z.; Meers, E.; Michels, E.; Hajdu, Z.; Spicnagel, A.M. The role of environmental attitudes and consumption patterns in consumers’ preferences for sustainable food from circular farming system: A six EU case studies. Agric Econ 2025, 13, 7. [Google Scholar] [CrossRef] [PubMed]
- Wu, H.; Yu, X.; Zhang, X.; Ipemba, E.; Bakala, G.B.; Leveut, L.G.D.; Peng, W.; Ji, F.; Li, H.; Cao, T.; et al. Impact of dietary Alpinia Katsumadai extracts on production performance, meat quality, and gene expression in AMPK signaling regulatory pathway of Wuzhishan pigs. Front. Vet. Sci. 2025, 12, 1563498. [Google Scholar] [CrossRef] [PubMed] [PubMed Central]
- Zhao, J. Analysis of the Rise and Fall of Pork Prices and Prediction of the Future Pork Market. Advances in Economics. Bus. Manag. Res. 2022, 211, 350–354. [Google Scholar] [CrossRef]
- Dong, D.; Stewart, H.; Dong, X.; Hahn, W. Quantifying Consumer Welfare Impacts of Higher Meat Prices During the COVID-19 Pandemic. Econ. Res. Rep. 2022, 306, 327177. [Google Scholar]
- Heber, L.; Petroman, C.; Petroman, I.; Balan, I.; Marin, I.; Ivascu, G.; Popovici, G. Pork and Carcasses Quality in Swine Exploited in FamilyFarms. Sci. Pap. Anim. Sci. Biotechnol. 2010, 43, 406. [Google Scholar]
- Beciu, S.; Arghiroiu, G.A. Challenges for the pork sector in Romania. Sci. Pap. Ser. Manag. Econ. Eng. Agric. Rural Dev. 2019, 19, 71–76. [Google Scholar]
- Balan, I.M.; Petroman, C.; Petroman, I.; Marin, D.; Ciolac, R.; Vaduva, L.; Manuela, D. Market Price of Romanian Pork Carcasses in 2009 Depending on Quality. Sci. Pap. Anim. Sci. Biotechnol. 2010, 43, 391. [Google Scholar]
- Pang, J.; Yin, J.; Lu, G.; Li, S. Supply and Demand Changes, Pig Epidemic Shocks, and Pork Price Fluctuations: An Empirical Study Based on an SVAR Model. Sustainability 2023, 15, 13130. [Google Scholar] [CrossRef]
- Ma, C.; Tao, J.; Tan, C.; Liu, W.; Li, X. Negative Media Sentiment about the Pig Epidemic and Pork Price Fluctuations: A Study on Spatial Spillover Effect and Mechanism. Agriculture 2023, 13, 658. [Google Scholar] [CrossRef]
- Popescu, A. Pork market crisis in Romania: Pig livestock, pork production, consumption, import, export, trade balance and price. Sci. Pap. Ser. Manag. Econ. Eng. Agric. Rural Dev. 2020, 20, 461–474. [Google Scholar]
- Soare, E.; Chiurciu, I.A.; Apostol, C.E.; Stoicea, P.; Dobre, C.A.; Iorga, A.M.; Bălan, A.V.; Frățoiu, A.R. Study on the worldwide pork market for the period 2015–2021. Sci. Pap. Ser. Manag. Econ. Eng. Agric. Rural Dev. 2024, 24, 2024. [Google Scholar]
- Hamulczuk, M.; Stańko, S. Factors affecting changes in prices and farmers’ income on the polish pig market. Zagadnienia Ekon. Rolnej/Probl. Agric. Econ. 2014, 341, 135–157. [Google Scholar] [CrossRef]
- Xu, F.; Ni, X.; Liu, K.; Wang, M.; Tan, K.; Hu, J. Analysis of pork price fluctuations during the special era when African swine fever and COVID-19 epidemic coexisted: An empirical study in Macau, China. Front. Sustain. Food Syst. 2024, 8, 1370726. [Google Scholar] [CrossRef]
- Nemteanu, M.-S.; Dinu, V.; Dabija, D.C. Job Insecurity, Job Instability, and Job Satisfaction in the Context of the COVID-19 Pandemic. J. Compet. 2021, 13, 65–82. [Google Scholar] [CrossRef]
- Steen, M.; Berglad, O.; Gjolberg, O. Climate Change and Grain Price Volatility: Empirical Evidence for Corn and Wheat 1971–2019. Commodities 2023, 2, 1–12. [Google Scholar] [CrossRef]
- Avelar, E.; Jha, R.; Beltranena, E.; Cervantes, M.; Morales, A.; Zijlstra, R.T. The effect of feeding wheat distillers dried grain with solubles on growth performance and nutrient digestibility in weaned pigs. Anim. Feed Sci. Technol. 2010, 160, 73–77. [Google Scholar] [CrossRef]
- Rosenfelder, P.; Eklund, M.; Mosenthin, R. Nutritive value of wheat and wheat by-products in pig nutrition: A review. Anim. Feed Sci. Technol. 2013, 185, 107–125. [Google Scholar] [CrossRef]
- Kim, J.C.; Simmins, P.H.; Mullan, B.P.; Pluske, J.R. The digestible energy value of wheat for pigs, with special reference to the post-weaned animal. Anim. Feed Sci. Technol. 2015, 122, 257–287. [Google Scholar] [CrossRef]
- Dinu, V. Competition’s Policy—A Tool to Protect Consumer’s Rights and Interests. Amfiteatru Econ. 2017, 19, 335–337. [Google Scholar]
- Kapoor, M.; Kelejian, H.H.; Prucha, I.R. Panel Data Models with Spatially Correlated Error Components. J. Econom. 2007, 140, 97–130. [Google Scholar] [CrossRef]
- Baltagi, B.H.; Bresson, G.; Pirotte, A. Panel Unit Root Tests and Spatial Dependence. J. Appl. Econom. 2007, 22, 339–360. [Google Scholar] [CrossRef]
- Lee, L.; Yu, J. Some Recent Developments in Spatial Panel Data Models. Reg. Sci. Urban Econ. 2010, 40, 255–271. [Google Scholar] [CrossRef]
- Baltagi, B.H.; Li, D. Prediction in the Panel Data Model with Spatial Correlation. In Advances in Spatial Econometrics; Springer: Berlin/Heidelberg, Germany, 2004; pp. 283–295. [Google Scholar] [CrossRef]
- Anselin, L. Spatial Econometrics: Methods and Models; Kluwer Academic: Dordrecht, The Netherlands, 1988. [Google Scholar] [CrossRef]
- LeSage, J.; Pace, R.K. Introduction to Spatial Econometrics, 1st ed.; Chapman and Hall/CRC: Boca Raton, FL, USA, 2009. [Google Scholar] [CrossRef]
- Bui, N.; Wen, L.; Sharp, B. House Prices and Flood Risk Exposure: An Integration of Hedonic Property Model and Spatial Econometric Analysis. J. Real Estate Finan. Econ. 2024, 69, 100–131. [Google Scholar] [CrossRef]
- Verhaagh, M. Comparison of the Competitiveness for Danish, Dutch, and German Piglet Producers under Consideration of Country-Specific Methods of Piglet Castration with Anesthesia. Agriculture 2024, 14, 1943. [Google Scholar] [CrossRef]
- Pawłowski, K.P.; Firlej, P.K.; Pietrzak, K.; Bartkowiak, Z.; Sołtysiak, G. The Maintenance System and Profitability of Pig Production in Poland Under Conditions of ASF Occurrence. Agriculture 2025, 15, 43. [Google Scholar] [CrossRef]
- Zehra, N. Factors affecting food prices in Pakistan. Pak. Dev. Rev. 2023, 62, 357–374. [Google Scholar] [CrossRef]
- Khan, M.; Schimmelpfennig, A. Inflation in pakistan: Money or wheat? IMF Work. Pap. 2006, 6, 1. [Google Scholar] [CrossRef]
- Enghiad, A.; Ufer, D.; Countryman, A.; Thilmany, D. An overview of global wheat market fundamentals in an era of climate concerns. Int. J. Agron. 2017, 2017, 1–15. [Google Scholar] [CrossRef]
- Zhou, C. An improved quantitative model for evaluating pork price fluctuation trend and the impaction in china: An empirical analysis between 2004–2014. Int. J. Future Gener. Commun. Netw. 2016, 9, 199–210. [Google Scholar] [CrossRef]
- Rensburg, E.; Casey, N.; Jordaan, J.; Webb, E. Price dynamics of red meat types in south africa for the period 2013 to 2017. Vet. Anim. Sci. 2020, 9, 100113. [Google Scholar] [CrossRef]
- Janković, I.; Kovačević, V.; Jeločnik, M. Production costs and market price of wheat behavior analysis as a support for hedging strategies. Ekon. Poljopr. 2020, 67, 495–509. [Google Scholar] [CrossRef]
- Slade, P.; Gray, R. Wheat stocks and the cointegration of wheat prices. Can. J. Agric. Econ./Rev. Can. D Agroecon. 2018, 67, 103–114. [Google Scholar] [CrossRef]
- Svanidze, M.; Götz, L.; Djuric, I.; Glauben, T. Food security and the functioning of wheat markets in eurasia: A comparative price transmission analysis for the countries of central asia and the south caucasus. Food Secur. 2019, 11, 733–752. [Google Scholar] [CrossRef]
- Cicia, G.; Caracciolo, F.; Cembalo, L.; Giudice, T.; Grunert, K.; Krystallis, A.; Lombardi, P.; Zhou, Y. Food safety concerns in urban china: Consumer preferences for pig process attributes. Food Control 2016, 60, 166–173. [Google Scholar] [CrossRef]
- Lü, J.; Wu, L.; Wang, S.; Xu, L. Consumer preference and demand for traceable food attributes. Br. Food J. 2016, 118, 2140–2156. [Google Scholar] [CrossRef]
- Wu, L.; Xu, L.; Zhu, D.; Wang, X. Factors affecting consumer willingness to pay for certified traceable food in jiangsu province of china. Can. J. Agric. Econ./Rev. Can. D Agroecon. 2012, 60, 317–333. [Google Scholar] [CrossRef]
- Ba, H.; Song, D.; Seol, K.; Kang, S.; Kim, H.; Moon, S.; Min, Y.-J.; Cho, S. Carcass trait, meat yield and quality characteristics of recently-synthesized woori heukdon and commercial lyd pigs under identical rearing condition. Anim. Biosci. 2023, 36, 943–952. [Google Scholar] [CrossRef]
- Lusk, J.; Tonsor, G. How meat demand elasticities vary with price, income, and product category. Appl. Econ. Perspect. Policy 2016, 38, 673–711. [Google Scholar] [CrossRef]
- Chen, J.; Fang, Z. The role of income and food prices in diet-related greenhouse gas emissions in China: A path towards a sustainable diet. Foods 2022, 11, 4051. [Google Scholar] [CrossRef]
- Lusk, J.; Tonsor, G.; Schroeder, T.; Hayes, D. Effect of government quality grade labels on consumer demand for pork chops in the short and long run. Food Policy 2018, 77, 91–102. [Google Scholar] [CrossRef]
- Zhong, F.; Wang, F.; Hao, R.; Wu, L. Agricultural science and technology innovation, spatial spillover and agricultural green development—Taking 30 provinces in China as the research object. Appl. Sci. 2022, 12, 845. [Google Scholar] [CrossRef]
- Hazrana, J.; Birthal, P.; Negi, D.; Mani, G.; Pandey, G. Spatial spill-overs, structural transformation and economic growth in India. Agric. Econ. Res. Rev. 2019, 32, 145. [Google Scholar] [CrossRef]
- Zhou, Y.; Li, W.; Li, H.; Zhen, W.; Zhang, B.; Zhong, K. impact of water and land resources matching on agricultural sustainable economic growth: Empirical analysis with spatial spillover effects from yellow river basin, China. Sustainability 2022, 14, 2742. [Google Scholar] [CrossRef]
- Sirohi, J.; Hloušková, Z.; Bartoňová, K.; Malec, K.; Maitah, M.; Koželský, R. The vertical price transmission in pork meat production in the Czech republic. Agriculture 2023, 13, 1274. [Google Scholar] [CrossRef]


| Pesaran’s test of cross-sectional independence | 43.271 (p-value: 0.000) |
| Average absolute value of the off-diagonal elements | 0.762 |
| Models | ||||
|---|---|---|---|---|
| Coefficients | OLS | SDM Random Effects | SDM Fixed Effects | SAC |
| Constant | 3.764584 *** | 1.522482 *** | - | - |
| Wheat price | 0.2714834 *** | 0.0486582 *** | 0.1879952 *** | 0.1724461 *** |
| Annual net earning | 0.057659 ** | 0.2994138 *** | 0.2975839 *** | 0.2745334 *** |
| W wheat price | - | −0.2400977 *** | −0.3388913 *** | - |
| W annual net earning | - | −0.608515 *** | −0.2354983 | - |
| Rho | - | 1.323524 *** | 1.340298 *** | 0.7792935 *** |
| Lambda | - | - | - | 1.119499 *** |
| Information criterion | ||||
| Akaike | −455.6632 | −602.8598 | −619.7234 | |
| Bayesian | −426.8758 | −581.2693 | −601.7313 | |
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content. |
© 2025 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
Share and Cite
Dinu, M.; Beia, S.I.; Pătărlăgeanu, S.R.; Gheorghe, A.F.; Munteanu, I.D.; Sacală, M.D. Exploring the Impact of Wheat Prices and Annual Income on Pig Carcass Prices in European Countries: A Spatial Panel Regression Analysis. Agriculture 2025, 15, 2216. https://doi.org/10.3390/agriculture15212216
Dinu M, Beia SI, Pătărlăgeanu SR, Gheorghe AF, Munteanu ID, Sacală MD. Exploring the Impact of Wheat Prices and Annual Income on Pig Carcass Prices in European Countries: A Spatial Panel Regression Analysis. Agriculture. 2025; 15(21):2216. https://doi.org/10.3390/agriculture15212216
Chicago/Turabian StyleDinu, Mihai, Silviu Ionuț Beia, Simona Roxana Pătărlăgeanu, Alina Florentina Gheorghe, Irina Denisa Munteanu, and Mihail Dumitru Sacală. 2025. "Exploring the Impact of Wheat Prices and Annual Income on Pig Carcass Prices in European Countries: A Spatial Panel Regression Analysis" Agriculture 15, no. 21: 2216. https://doi.org/10.3390/agriculture15212216
APA StyleDinu, M., Beia, S. I., Pătărlăgeanu, S. R., Gheorghe, A. F., Munteanu, I. D., & Sacală, M. D. (2025). Exploring the Impact of Wheat Prices and Annual Income on Pig Carcass Prices in European Countries: A Spatial Panel Regression Analysis. Agriculture, 15(21), 2216. https://doi.org/10.3390/agriculture15212216

