20 SOCIAL SCIENTIST In the third place, there is naturalization which makes it impossible to track the number of immigrant workers, because they now have the nationality of their new mother country. Comparing the figures mentioned in various publications it seems that a reasonable estimate for 1985 would be the presence of 10 million immigrants in the Middle East. About 55 per cent of these came from other Arab countries in the Middle East. About 40 per cent of the population in the oil countries of the Middle East are immigrants, and in some countries this percentage goes up to 80 per cent. There is a remarkable difference with the situation in 1975 when there were 'only* 3 million immigrants (25 per cent of the total population) of which 65 per cent were Arabs. An additional issue to take into account is that the aforementioned figures are static i.e. the result of a count at a certain moment in time. The number of people who over the years have participated in labor migration to the oil countries is of course larger. For example, for Egypt the estimate is that between 1974 and 1984 about 3.5 million people participated in the migration process of which 2.8 million were labourers and the remaining consisted of accompanying relatives (Fergany, 1988). THE POLITICO-ECONOMICAL CONTEXT Basically, the large scale international labor migration to the oil countries in the Middle East can be accounted for by the existence of, on the one hand, oil-producing countries with a relatively small population, and, on the other, the non-(or hardly) oil producing countries (also in the Middle East or in South Asia and East Asia) with a large population. The first category of countries consists of Saudi Arabia (7 millions inhabitants), Kuwait (1.3 million), the United Arab Emirates (UAE, 1 million), Oman (0.8 million) and Libya (3 million). These countries have an average income per capita of US$ 16,000 per year. The second category consists of countries like Egypt (with 47 million inhabitants). North Yemen (6 million). South Yemen (2 million), Jordan (3 million), Lebanon (3 million), and Syria (9 million). The average yearly income in these countries is about US$ 700 per capita. The aforementioned fast growth between 1975 and 1985 of migrant workers is directly related to the explosive increase of oil prices from 1973 onwards. Inl973 the price of a barrel was only US$1.83, two years later it was up to US$11.5. With leaps and bounds it grew to US$26 in 1979 and to US$34 by the end of 1981. In 1970 the revenues for the oil producing countries in the Middle East amounted to US$5 billion, in 1980 it had grown to US$200 billion. Just for Saudi Arabia alone the revenue in this period of ten years went up from US$1 billion to US$100 billion. At the same time the debts of the poor Arabian countries increased steadily. Egypt's foreign debt increased from US$2 billion in 1970