Riches get their value from the mind of the possessor; they are blessings to those who know how to use them, and curses to those who do not.
I am going to analise two important phenomenas that affect a country development: The Dutch Disease and The Democracy Effect in Economy. I will start with the former and analyse the later in my next post.
Dutch disease is named after the effect that the discovery of natural gas had in Holland in the 1960s. It is also called the Resource Trap but it can originate not only in natural resources discovery, but in any development in that results in a large inflow of foreign currency, including a sharp surge in natural resource prices, foreign assistance, and foreign direct investment.
Imagine first a country like Japan in the 1950s, with not natural resources. Japanese people want to buy imports, but they can only do so with hard currency, so they need to produce exports to get it. Exports (tradable goods) would sell in hard currency and sell it to importers who will use it to buy imports and sell them in Japan. Exports in such cases are manufactured products and some services (and some natural resources in a limited fashion), so the country start producing in order to import goods that lacks, making the national industry important and competitive. The local non-tradable good and services (like restaurants) get some of the money since people increase their standard of living, elevating the price of these non-tradable goods and services, and attracting some labour
Imagine then a country that discovers oil or gas or diamonds. This natural resource is sold in the international markets, creating a surge in the inflow of hard currency to the country. Since the price of tradeable goods is set internationally, the laws of supply and demand make rise the exchange rate of the country in question, hence making the rest of the exports in the country less competitive. Additionally, the extra revenue make non-tradeable goods and service more expensive in the country since there is more money to be spent and demand for new items.
Example, in the 1970s, Nigeria exported peanuts and cacao, then the oil revenues started to build up, and the Nigerian currency gain value, making their peanuts and cacao too expensive. Both industries collapsed. When prices eventually went down, the growth and standard of living of Nigerians was halved.
So the ill effect comes when the resource runs out or when the price goes down. The manufacturing industry has been badly damaged and cannot compete in international markets. All the foreign investment went towards the natural resource, and nothing to the traditional manufacturing sector. The country then stops development and spiral down.
Foreign Aid has the same effect that a natural resource discovery: It brings unearned hard currency to a country, making his own currency more expensive and killing its exports.
Hence, a sudden surge in the foreign currency inflows to a country make this country uncompetitive in the global markets, killing his tradable sector, making his non-tradable sector more expensive, and slowing the growth in the long run.
Now with pictures: In a normal economy without lots of natural resources, the manufacture sector is big (blue), some people and employ in services (green), and very few are in the natural resources sector (red) and, with hope, very few are unemployed (grey)
Then oil is discovered and a boom starts. The booming sector attracts all the labour force and foreign investment, while the traditional sector lags behind and gets reduced. The non-tradeable sector grows a little since there is a new demand for its goods and products, and draws some of the capital and labour, making these goods and services more expensive and in further detriment of the traditional sector. The excesive exports of the natural resource make the currency so expensive that further damages the traditional tradeable industry.
After some years or decades, the natural resources either ran out or the international prices plumbed. The former boom sectors shrinks, laying out people, the demand for non-tradable good and services shrinks too, laying out people, and the traditional manufactures are now too small to accommmodate the excess of labour. No further investment is done, and unemployment rises.