The Resource Curse

The [African] blog wars writes about the 'Resource Curse':

It is widely suspected that the ‘curse’ is largely caused by the effects of over-dependence on resources. Governments, perhaps believing resources will never run dry (in their time), fail to wean economies off these commodities. One of the consequences of this is that in times of high prices, the real exchange rate rises making local industries less competitive, while encouraging borrowing as it becomes relatively cheaper to do so.
The danger though is when prices fall, exchange rates fall and debt repayments soar, and this is after industries have contracted, which dramatically decreases tax revenues. Sure, taxes could be pushed up to compensate, but this wouldn't do much for competitiveness.
Over-dependence is the big issue though. Botswana still gets 70 percent of its export revenues from diamonds, while Burundi, Rwanda and Uganda all earn more than 50 of their export earnings from coffee. Looking west to cotton producing nations, the picture isn’t really any better. And, then, of course, there’s oil, which earns Nigeria 95 percent of its export income. Perhaps part of Chad’s defection to China was because the Asian giant is more likely to be able to buy all of Chad’s oil than Taiwan is.