International trade is one of the most powerful engines of economic growth. But why do countries trade at all? Why not produce everything domestically?

Comparative Advantage

The key insight, from economist David Ricardo: countries should specialize in producing goods where they have the lowest opportunity cost, even if they're not the absolute best at anything.

Example: India has a comparative advantage in IT services (abundant skilled engineers, lower costs). The US has a comparative advantage in advanced semiconductors. Both countries are better off if India exports IT services and imports chips.

Benefits of Trade

• Lower prices — Competition from imports keeps domestic prices down
• Greater variety — Consumers get access to goods not produced locally
• Economies of scale — Firms can produce for a global market, reducing per-unit costs
• Technology transfer — Trade exposes countries to new technologies and methods

Arguments Against Free Trade

• Job displacement — Workers in uncompetitive industries lose jobs
• Infant industry — New domestic industries may need protection from established foreign competitors
• National security — Some industries (defense, semiconductors) are too critical to depend on imports
• Environmental — Trade can shift pollution to countries with weaker regulations