A Causal Exploration of Conflict Events and Commodity Prices of Sudan

Chen, Junyi and Kibriya, Shahriar and Bessler, David and Price, Edwin (2015): A Causal Exploration of Conflict Events and Commodity Prices of Sudan.

Abstract

Though recent literature uncovers linkages between commodity prices and conflict, the causal direction of the relationship remains ambiguous. We attempt to contribute in this strand of research by studying the dynamic relationship of commodity prices and the onsets of conflict events in Sudan. Using monthly data ranging from January 2001 through December 2012, we identify a structural breakpoint in the multivariate time series model of prices of the three staple foods (sorghum, millet, and wheat) and conflict measure (number of conflict events) in September of 2011. Applying Structure Vector Autoregression (SVAR) and Linear Non-Gaussian Acyclic Model (LiNGAM), we find that wheat price is a cause of conflict events in Sudan. We find no feedback from conflict to commodity prices.

• Item Type: MPRA Paper
• Language: English
• Keywords: Commodity Prices, Conflict, Sudan
• Subjects: C - Mathematical and Quantitative Methods > C5 - Econometric Modeling > C54 - Quantitative Policy Modeling; O - Economic Development, Innovation, Technological Change, and Growth > O1 - Economic Development; Q - Agricultural and Natural Resource Economics ; Environmental and Ecological Economics > Q0 - General > Q02 - Commodity Markets

References

Abdelrahman, A. H. (1998). Trends in Sudanese cereal production, consumption, and trade. Center for Agricultural and Rural Development, Iowa State University.

Auad, M. E., Elmulathum, N. A., & Elamin, A. E. (2007). Estimation of supply and demand functions of the major food security crops in the Sudan (1974-2004). Gezira Journal of Agricultural Science, 5(2).

Bai, J., & Perron, P. (1998). Estimating and testing linear models with multiple structural changes. Econometrica, 47-78.

Bai, J., & Perron, P. (2003). Computation and analysis of multiple structural change models. Journal of Applied Econometrics, 18(1), 1-22.

Bellemare, M. F. (2011). Rising food prices, food price volatility, and political unrest. (June 28, 2011). Available at SSRN: http://ssrn.com/abstract=1874101 or http://dx.doi.org/10.2139/ssrn.1874101.

Berazneva, J., & Lee, D. R. (2013). Explaining the African food riots of 2007–2008: An empirical analysis. Food Policy, 39, 28-39.

Bernanke, B. S. (1986). Alternative explanations of the money-income correlation. Paper presented at the Carnegie-Rochester Conference Series on Public Policy, 25, 49-99.

Besley, T. J., & Persson, T. (2008). The incidence of civil war: Theory and evidence (No. w14585). National Bureau of Economic Research.

Bessler, D. A. (1984). Additional evidence on money and prices: US data 1870–1913. Explorations in Economic History, 21(2), 125-132.

Bessler, D. A., & Akleman, D. G. (1998). Farm prices, retail prices, and directed graphs: results for pork and beef. American Journal of Agricultural Economics, 80(5), 1144-1149.

Bessler, D. A., & Kling, J. L. (1984). A note on tests of Granger causality. Applied Economics, 16(3), 335-342.

Bhatt, V., & Kishor, N. K.. (2015).Are all movements in food and energy prices transitory? Evidence from India. Journal of Policy Modeling.

Blattman, C., & Miguel, E. (2010). Civil war. Journal of Economic Literature, 3-57.

Briiggemann, R., & Liitkepohl, H. (2001). Lag selection in subset VAR models with an application to a US monetary system. Econometric Studies: A Festschrift in Honour of Joachim Frohn (R. Friedmann, L. Knuppel, H. Lutkepohl, Eds.), LIT-Verlag, Miinster, 107-128.

Brinkman, H., & Hendrix, C. S. (2011). Food insecurity and violent conflict: causes, consequences, and addressing the challenges. Occasional Paper, 24, 513-520.

Brückner, M., & Ciccone, A. (2010). International commodity prices, growth and the outbreak of civil war in sub‐Saharan Africa. The Economic Journal, 120(544), 519-534.

Chickering, D. M. (2003). Optimal structure identification with greedy search. The Journal of Machine Learning Research, 3, 507-554.

Collier, P., & Hoeffler, A. (1998). On economic causes of civil war. Oxford Economic Papers, 50(4), 563-573.

Collier, P., & Hoeffler, A. (2004). Greed and grievance in civil war. Oxford Economic Papers, 56(4), 563-595.

Demuynck, T., & Schollaert, A. (2008). International commodity prices and the persistence of civil conflict (No. 08/518). Ghent University, Faculty of Economics and Business Administration.

Doan, T. (2010) Rats User’s Manual: Version 8.0, Estima, Evanston, IL

FAO/WFP. (2011). Special report: government of Sudan and FAO/WFP crop and food security assessment mission to the 15 northern states of Sudan.

FAO/WFP. (2014). Special report: crop and food security assessment mission to South Sudan.

FAO–SIFSIA. (2012). Soaring food prices and its policy implications in North Sudan: a policy brief.

FEWS NET. (2014a). Sudan Price Bulletin.

FEWS NET. (2014b). Sudan Food Security Outlook.

Goldstone, J. A. (1982). The comparative and historical study of revolutions. Annual Review of Sociology, 8, 187-207.

Goldstone, J. A. (2002). Population and security: how demographic change can lead to violent conflict. Journal of International Affairs, 56(1), 3-21.

Guidolin, M., & La Ferrara, E. (2010). The economic effects of violent conflict: evidence from asset market reactions. Journal of Peace Research, 47(6), 671-684.

Hadley, C., Stevenson, E. G. J., Tadesse, Y., & Belachew, T. (2012). Rapidly rising food prices and the experience of food insecurity in urban Ethiopia: impacts on health and well-being. Social Science & Medicine, 75(12), 2412-2419.

Hamid, B. H. (2003). Overview of Sorghum and Millet in Sudan. Ministry of Science and Technology, Agricultural Research Corporation (ARC), Food Research Center.

Hannan, E. J., & Quinn, B. G. (1979). The determination of the order of an autoregression. Journal of the Royal Statistical Society. Series B (Methodological), 190-195.

Hitzhusen, F. J., & Jeanty, P. W. (2006). Analyzing the effects of conflicts on food security in developing countries: An instrumental variable panel data approach. Annual Meeting of the American Agricultural Economics Association, July 23–26, Long Beach, CA.

Hsiao, C. (1979). Autoregressive modeling of Canadian money and income data. Journal of the American Statistical Association, 74(367), 553-560.

Hyvärinen, A. (1999). Fast and robust fixed-point algorithms for independent component analysis. Neural Networks, IEEE Transactions on, 10(3), 626-634.

Hyvärinen, A., Karhunen, J., & Oja, E. (2004). Independent component analysis. John Wiley & Sons. IFAD. (2009). Republic of the Sudan, Country Programme Evaluation. Report No. 2060-SD.

Jarque, C. M., & Bera, A. K. (1980). Efficient tests for normality, homoscedasticity and serial independence of regression residuals. Economics Letters, 6(3), 255-259.

Jarque, C. M., & Bera, A. K. (1987). A test for normality of observations and regression residuals. International Statistical Review/Revue Internationale De Statistique, 163-172.

Jayne, T. S., Mason, N. M., Myers, R. J., Ferris, J. N., Mather, D., Beaver, M., ... & Boughton, D. (2010). Patterns and trends in food staples markets in Eastern and Southern Africa: toward the identification of priority investments and strategies for developing markets and promoting smallholder productivity growth (No. 62148). Michigan State University, Department of Agricultural, Food, and Resource Economics.

Kling, J. L., & Bessler, D. A. (1985). A comparison of multivariate forecasting procedures for economic time series. International Journal of Forecasting, 1(1), 5-24.

Kollias, C., Kyrtsou, C., & Papadamou, S. (2011). The effects of terrorism and war on the oil and prices-stock indices relationship. Economics of Security Working Paper, 57.

Lagi, M., Bertrand, K. Z., & Bar-Yam, Y. (2011). The food crises and political instability in North Africa and the Middle East. Available at SSRN 1910031.

Letiche, J. M. (2010). Transforming sub-Saharan Africa. Journal of Policy Modeling, 32(2), 163-175.

Lambert, D. K., & Miljkovic, D. (2010). The sources of variability in US food prices. Journal of Policy Modeling, 32(2), 210-222.

Mahran, H. A. (1996). Food security in Sudan: the response to technological change: proceedings of the international symposium on food security and innovations: successes and lessons learnt. University of Hohenheim, Germany, 155-165.

Miguel, E., Satyanath, S., & Sergenti, E. (2004). Economic shocks and civil conflict: an instrumental variables approach. Journal of Political Economy, 112(4), 725-753.

Misselhorn, A. A. (2005). What drives food insecurity in southern Africa? A meta-analysis of household economy studies. Global Environmental Change, 15(1), 33-43.

Moneta, A., Entner, D., Hoyer, P. O., & Coad, A. (2013). Causal inference by independent component analysis: theory and applications*. Oxford Bulletin of Economics and Statistics, 75(5), 705-730.

Mustafa, R. H., Elgali, M. B., & Abulgasim, S. (2013). Trends in wheat production and consumption in Sudan. International Journal of Research in Management, Economics and Commerce, 3(4), 44-56.

Raleigh, C., Linke, A., Hegre, H., & Karlsen, J. (2010). Introducing acled: an armed conflict location and event dataset special data feature. Journal of Peace Research, 47(5), 651-660.

Ramsey, J., Spirtes, P., Scheines, R., & Glymour, C. (2013). Tetrad IV.

Say, W. O., Sapolsky, H., Payne, R., Vale, P., Aaronson, M., Hill, M. A., & Cox, D. G. (2012). Is Identity the Root Cause of Sudan’s Civil Wars?

Shimizu, S. (2014). LiNGAM: Non-Gaussian methods for estimating causal structures. Behaviormetrika, 41(1), 65-98.

Shimizu, S., Hoyer, P. O., Hyvärinen, A., & Kerminen, A. (2006). A linear non-Gaussian acyclic model for causal discovery. The Journal of Machine Learning Research, 7, 2003-2030.

Sims, C. A. (1980). Macroeconomics and reality. Econometrica: Journal of the Econometric Society, 48, 1-48.

Smith, T. (2013). Food price spikes and social unrest in Africa. CCAPS Research Brief, (11).

Smith, T. G. (2014). Feeding unrest disentangling the causal relationship between food price shocks and sociopolitical conflict in urban Africa. Journal of Peace Research, 51(6), 679-695.

Spirtes, P., Glymour, C., & Scheines, R. (2000). Causation, prediction, and search (Vol. 81). The MIT Press. Swanson, N. R., & Granger, C. W. (1997). Impulse response functions based on a causal approach to residual orthogonalization in vector autoregressions. Journal of the American Statistical Association, 92(437), 357-367.

Walton, J. K., & Seddon, D. (2008). Free markets and food riots: The politics of global adjustment. John Wiley & Sons.