The first is that of absorbing labour that has been freed up from the subsistence sector. The second is that of generating foreign exchange revenues, which in turn is necessary for importing essential goods and servicing foreign debt. The LDCs have been focusing on the tradables sector for the past 25 years, which has meant shifting resources to encourage exports and introducing policies conducive to export-led growth. This shift has generally been successful in increasing foreign exchange earnings. Export revenues rose vigorously during the 2000s, since both the volumes exported and the prices of exported goods expanded. Where exports are based on natural resource extraction, the employment intensity of growth has been low.