How was Arthur Lewis awarded the Noble Prize in Economics?

Name: Arthur Lewis.
Real Name: William Arthur Lewis.
Country: Saint Lucia, United Kingdom.
Date of Birth: January 23, 1915.
Died: June 15, 1991.
Education:  Graduation and Doctor of Philosophy (Ph.D.) from London School of Economics.
Subjects Of Study: Economic development international trade productivity economic model industrial country.
Popularly Known: Development economics, Dual-sector model, Lewis turning point, Industrial structure, History of the world economy.
Noble Prize Year: Nobel Prize for Peace in 1979, for their pioneering research into economic development research with particular consideration of the problems of developing countries.