While consumers are experiencing something of a windfall as the oil price falls, the precipitous decline is not good news all round. Those African governments that have become reliant on oil-linked revenues are deeply concerned. The decline has also dampened prospects for hard-mineral prices, which have already weakened materially. The net effect on South Africa, which is a commodity exporter and oil importer, will become clearer in the months ahead. But the risks appear weighted to the downside, as they are for this shale-energy worker pictured outside Midland, Texas.