The present paper provides a literature review of studies examining the potential causes and consequences of recent surges in food and agricultural commodity prices. Furthermore, this paper uses the structural trend methodology proposed by Koopman et al. (2009) to analyze movements in the IMF monthly commodity food price index for the period 1992(11)–2012(10) and to provide forecasts for the period 2012(11)–2014(12). The empirical results indicate that commodity food prices present seasonality and cyclicality with the longest periodicity of two years. The empirical findings identify certain structural breaks in commodity food price series as well as outliers. These structural breaks seem to capture the trend component of the price series well, while the outliers take account of temporal effects, that is, short-lived spikes. Finally, the presented forecasts show high and volatile commodity food prices. 1. Introduction Commodity food prices have surged upwards in dramatic fashion in recent years after several decades of relative stability and low levels. In particular, commodity food prices increased dramatically between late 2006 and mid-2008, and by reaching high levels later on (i.e., during 2010, early 2011, and the third quarter of 2012), they caused serious concerns about a repeat of the 2006–2008 food crisis. This phenomenon has motivated several analyses of the factors that have caused commodity food prices to increase in recent years. The purpose of the present paper is twofold. First, it reviews the empirical studies that identify and analyze the possible causes of the recent food and agricultural commodity spikes. Second, it uses a structural time series approach to analyze the behavior of the monthly commodity food price index for the past 20 years. In the empirical part, the present paper departs from previous detrending methods and employs a structural time series approach , which provides the possibility of discovering commodity price cycles. Furthermore, this approach permits not only the possibility of stochastic cycles but also the presence of stochastic trends in levels and growth rates and provides efficient forecasts on the commodity food price index. The remainder of this paper is organized as follows. Section 2 presents and discusses the literature on the causes of commodity food price increases in recent years. In Section 2.1, specific discussion is devoted to the possible linkages between fuel and food prices, while in Section 2.2 the possible relation between speculation and food prices is provided. Section 3 presents the
A. Prakash and C. L. Gilbert, “Rising vulnerability in global food system: beyond market fundamentals,” in Safeguarding Food Security in Volatile Global Markets,, A. Prakash, Ed., FAO, Rome, Italy, 2011.
G. A. Cornia, L. Deotti, and M. Sassi, “Food price volatility over the last decade in Niger and Malawi: extent, sources and impact on child malnutrition,” Working Paper 2012-002, UNDP, Regional Bureau for Africa, 2012.
D. Headey and S. Fan, Reflections on the Global Food Crisis. How Did It Happen? How Has It Hurt? And How Can We Prevent the Next One?International Food Policy Research Institute, Washington, DC, USA, 2010.
M. W. Rosegrant, S. Msangi, T. Sulser, and R. Valmonted-Santos, “Biofuels and the global food balance,” in Bioenergy and Agriculture: Promises and Challenges, P. Hazell and R. K. Pachauri, Eds., IFPRI, Washington, DC, USA, 2006.
S. Wiggins, E. Fioretti, J. Keane et al., Review of the Indirect Effects of Biofuels: Economic Benefits and Food Insecurity, Overseas Development Institute, 2008, http://www.dft.gov.uk/rfa/_db/_documents/ODI_Economic_benefits_and_food_insecurity.pdf.
S. Pfuderer, G. Davies, and I. Mitchell, “The role of demand for biofuel in the agricultural commodity price spikes of 2007/08. Annex 5,” in The 2007/08 Agricultural Price Spikes: Causes and Implications, UK Government, Ed., 2010, http://www.growthenergy.org/images/reports/UKgov_Ag_Price_Spikes.pdf.
G. Hochman, D. Rajagopal, D. Timilsina, and D. Zilberman, “The role of inventory adjustments in quantifying factors causing food price inflation,” Policy Research Working Paper 5744, Development Research Group, Environment and Energy Team, The World Bank, Washington, DC, USA, August 2008.
D. M. Arseneau and S. Leduc, “Commodity Price Movements in a General Equilibrium Model of Storage,” Unpublished manuscript, 2012, http://www.imf.org/external/np/seminars/eng/2011/tur/pdf/Arseneau-Leduc.pdf.
J. von Braun and G. Tadesse, “Global food price volatility and spikes: an overview of costs, causes, and solutions,” ZEF-Discussion Papers on Development Policy 161, University of Bonn Center for Development Research, Bonn, Germany, 2012.
S. H. Irwin, D. R. Sanders, and R. P. Merrin, “Devil or angel? The role of speculation in the recent commodity price boom (and bust),” Journal of Agricultural and Applied Economics, vol. 41, no. 2, pp. 377–391, 2009.
P. Cashin and C. J. McDermott, “Properties of international commodity prices: identifying trend, cycles and shocks,” in Agricultural Commodity Markets and Trade: New Approaches to Analyzing Market Structure and Instability, A. Sarris and D. Hallam, Eds., pp. 16–30, Food and Agricultural Organization of the United Nations and Edward Elgar, Cheltenham, UK, 2006.