In economics, the Dutch disease is the apparent causal relationship between the increase in the economic development of a specific sector (for example natural resources) and a decline in other sectors (like the manufacturing sector or agriculture). The putative mechanism is that as revenues increase in the growing sector (or inflows of foreign aid), the given nation's currency becomes stronger (appreciates) compared to currencies of other nations (manifest in an exchange rate). This results in the nation's other exports becoming more expensive for other countries to buy, and imports becoming cheaper, making those sectors less competitive.