This accompanied with the fact that all of them except for Saudi Arabia, have considerably smaller populations of indigenous people as compared to other countries of the world, makes the supply far in excess of the demand.Most of these Gulf states run short of indigenous labor. In order to accommodate the shortage of labor, every year, thousands of migrants are allowed to work in these states most of which come from such South Asian countries as India, Pakistan and Bangladesh.Oil and gas are the biggest and the fundamental sources of revenue for all of the Gulf countries. In addition to the reserves of oil and gas, many Gulf states that include but are not limited to Bahrain, Qatar, Kuwait and United Arab Emirates have long been earning a lot from the business of pearl diving. This is also the main reason why the per capita income of the Gulf countries is much more than other countries in their neighborhood. The pearl industries had flourished in these Gulf states over the years and had become one of the most significant economy drivers of these countries until early 1930s, when Japan developed many methods of cultured pearls and became a greater producer of pearls. Recently, economic recession has blanketed the whole world because of several political upsets and other reasons, though the Gulf countries have sustained their economic strength.