Early economists wanted to settle the question of whether trade with other countries was good or whether it was to be avoided as the mercantilists advised. Trade was thought to be a zero-sum game; a country could gain only at the expense of others. As manufacturing took hold, England made great strides in the production of coal, iron and steel, and textiles. Relentless technological push and investment gave it the ability to serve bigger markets by the early nineteenth century. The International Monetary Fund (IMF) was conceived to help the settlement of claim among countries arising from trade deficits. It established a clearing system for these transactions. General Agreement on Tariffs and Trade (GATT) was planned to promote international trade by reducing protection and trade barriers. Migration is the direct movement of labour from one country to another. It has shaped the demography of the world as it is today.