Speculation and food-grain prices

The impact of speculative activities in financial markets on food-grain prices is a topical but debated issue. We consider four major food-grain commodities and several speculation measures–which represent different underlying definitions of speculation–in structural vector autoregression models to examine this issue empirically. Results show that the impact of speculation depends on the commodity in question (rice and wheat are generally less sensitive than corn and soybean) and the measure of speculation used. Further analysis shows that traders’ behaviour in the futures market is different for wheat and rice, around 80% of which are directly used for human consumption, compared to corn and soybean, only around 15% of which are directly used as human food. We also show that the heterogeneous effect of different speculative measures is mostly due to their construction. Results are robust to various modifications of the models. From a policy perspective, we think a blanket regulation for all the commodities may not be optimal.