No abstract

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International licence Newcastle University ePrints-eprint.ncl.ac.uk

This paper empirically examines the time series behavior of primary commodity prices relative to manufactures with reference to the nature of their underlying trends and the persistence of shocks driving the price processes. The direction and magnitude of the trends are assessed employing a set of econometric techniques that is robust to the nature of persistence in the commodity price shocks, thereby obviating the need for unit root pretesting. Specifically, the methods allow consistent estimation of the number and location of structural breaks in the trend function as well as facilitate the distinction between trend breaks and pure level shifts. Further, a new set of powerful unit root tests is applied to determine whether the underlying commodity price series can be characterized as difference or trend stationary processes. These tests treat breaks under the unit root null and the trend stationary alternative in a symmetric fashion thereby alleviating the procedures from spurious rejection problems and low power issues that plague most existing procedures. Relative to the extant literature, we find more evidence in favor of trend stationarity suggesting that real commodity price shocks are primarily of a transitory nature. We conclude with a discussion of the policy implications of our results.

No abstract

Commodity price shocks are an important type of external shock and are often cited as a problem for economic growth in Sub-Saharan Africa. We choose nine Sub-Saharan African countries that are heavily dependent on a single agricultural commodity for a significant portion of their income. This paper quantifies the impact of agricultural commodity price shocks using a structural non-linear dynamic model. The novel aspect of this study is that we determine whether the response of per capita GDP for the selected Sub-Saharan African countries is different to unexpected increases in agricultural commodity prices as opposed to decreases in prices. We conclude that there is very little evidence that an unanticipated price increase (decrease) will lead to a significantly different response in per capita incomes.

No abstract

No abstract

No abstract