There is a common perception that the prices of unrelated commodities move together. This paper re-examines this notion, using a measure of comovement of economic time series called concordance. Concordance measures the proportion of time that the prices of two commodities are concurrently in the same boom period or same slump period. Using data on the prices of several unrelated commodities, the paper finds no evidence of comovement in commodity prices. The results carry an important policy implication, as the study provides no support for earlier claims of irrational trading behavior by participants in world commodity markets.

This paper provides a comprehensive analysis of the degree of co-movement among the nominal price returns of 11 major energy, agricultural, and food commodities using monthly data between 1970 and 2013. The authors study the extent and the time evolution of unconditional and conditional correlations using a uniform-spacings testing approach, a multivariate dynamic conditional correlation model and a rolling regression procedure.

The behaviour of commodity prices never ceases to marvel economists, financial analysts, industry experts, and policymakers. Unexpected swings in commodity prices used to occur infrequently but have now become a permanent feature of global commodity markets. This book is about modelling commodity price shocks. It is intended to provide insights into the theoretical, conceptual, and empirical modelling of the underlying causes of global commodity price shocks. Three main objectives motivated the writing of this book. First, to provide a variety of modelling frameworks for documenting the frequency and intensity of commodity price shocks. Second, to evaluate existing approaches used for forecasting large movements in future commodity prices. Third, to cover a wide range and aspects of global commodities including currencies, rare–hard–lustrous transition metals, agricultural commodities, energy, and health pandemics. Some attempts have already been made towards modelling commodity price shocks. However, most tend to narrowly focus on a subset of commodity markets, i.e., agricultural commodities market and/or the energy market. In this book, the author moves the needle forward by operationalizing different models, which allow researchers to identify the underlying causes and effects of commodity price shocks. Readers also learn about different commodity price forecasting models. The author presents the topics to readers assuming less prior or specialist knowledge. Thus, the book is accessible to industry analysts, researchers, undergraduate and graduate students in economics and financial economics, academic and professional economists, investors, and financial professionals working in different sectors of the commodity markets. Another advantage of the book’s approach is that readers are not only exposed to several innovative modelling techniques to add to their modelling toolbox but are also exposed to diverse empirical applications of the techniques presented.

This paper examines the duration and magnitude of commodity-price cycles. It finds that for most commodities, price slumps last longer than price booms. How far prices fall in a slump is found to be slightly larger than how far they rebound in a subsequent boom. There is little evidence of a consistent ‘shape’ to commodity-price cycles. For all commodities, the probability of an end to a slump in prices is independent of the time already spent in the slump, and for most commodities, the probability of an end to a boom in prices is independent of the time already spent in the boom.

Recent economic growth in China and other Asian countries has led to increased commodity demand which has caused price rises and accompanying price fluctuations not only for crude oil but also for the many other raw materials. Such trends mean that world commodity markets are once again under intense scrutiny. This book provides new insights into the modeling and forecasting of primary commodity prices by featuring comprehensive applications of the most recent methods of statistical time series analysis. The latter utilize econometric methods concerned with structural breaks, unobserved components, chaotic discovery, long memory, heteroskedasticity, wavelet estimation and fractional integration. Relevant tests employed include neural networks, correlation dimensions, Lyapunov exponents, fractional integration and rescaled range. The price forecasting involves structural time series trend plus cycle and cyclical trend models. Practical applications focus on the price behaviour of more than twenty international commodity markets.

This book examines the issue of price volatility in agricultural commodities markets and how this phenomenon has evolved in recent years. The factors underlying the price spike of 2007-08 appear to be global and macroeconomic in nature, including the rapid growth in demand by developing countries, the international financial crisis, and exchange rate movements. Some of these factors are new, appearing as influences on price volatility only in the last decade. Although volatility has always been a feature of agricultural commodity markets, the evidence suggests that volatility has increased in certain commodity markets. A growing problem is that agricultural price shocks and volatility disrupt agricultural markets, economic incentives and incomes. With increased globalization and integration of financial and energy markets with agricultural commodity markets, the relationships between markets are expanding and becoming more complex. When a crisis such as a regional drought, food safety scare or a financial crisis hits a particular market, policy-makers often do not know the extent to which it will impact on other markets and affect producer, consumer and trader decisions. Including contributions from experts at the World Bank, the Food and Agriculture Organization of the United Nations, the USDA, and the European Commission, the research developed throughout the chapters of this book is based on current methodologies that can be used to analyze price volatility and provide directions for understanding this volatility and the development of new agricultural policies. The book highlights the challenges facing policy makers in dealing with the changing nature of agricultural commodities markets, and offers recommendations for anticipating price movements and managing their consequences. It will be a practical guide for both present and future policy-makers in deciding on potential price-stabilizing interventions, and will also serve as a useful resource for researchers and students in agricultural economics.