Two major examples of how the Middle East and its Muslim nations influenced the economy of Western Europe are:
Fossil fuels
Sugar trade
The fossil fuels in the Middle East drove the energy requirements of Western Europe with relation to crude oil such that the Western Europeans sought to control the area by any means necessary.
The sugar trade was also influential because sugar was mostly controlled by Muslims and until the Europeans got to the New World, they had to rely on the Muslims of the Middle East for it.
In conclusion, sugar and oil from the Middle East were very influential on Western Europe's economy.
If the population stays the same, an increase in GDP grows income per capita. There are several ways to increase GDP: Education and training. Greater education and job skills allow individuals to produce more goods and services, start businesses and earn higher incomes.
