when two countries trade they can each have a comparative advantage and benefit each other for instance imagine a country that has limited natural resources one day a shepherd stumbled upon an abundant cheap and renewable energy source only occurring within that country s borders that could provide enough clean energy for its neighboring countries for centuries as a result this country would suddenly have a comparative advantage it could market to trading partners 
imagine a neighboring country has a booming lumber trade and can manufacture building supplies much cheaper than the country with the new energy source but it consumes a lot of energy to do so the two countries have comparative advantages that can be traded beneficially for both benefits of tradebecause countries are endowed with different assets and natural resources some may produce the same good more efficiently and sell it more cheaply than others countries that trade can take advantage of the lower prices available in other countries here are some other benefits of trade 2criticisms of tradewhile the law of comparative advantage is a regular feature of introductory economics many countries try to shield local industries with tariffs subsidies or other trade barriers one possible explanation comes from what economists call rent seeking rent seeking occurs when one group organizes and lobbies the government to protect its interests for example business owners might pressure their country s government for tariffs to protect their industry from inexpensive foreign goods which could cost the livelihoods of domestic workers even if the business owners understand trade benefits they could be reluctant to sacrifice a lucrative income stream moreover there are strategic reasons for countries to avoid excessive reliance on free trade for example a country that relies on trade might become too dependent on the global market for critical goods some development economists have argued for tariffs to help protect infant industries that cannot yet compete on the global market as those industries grow and mature they are expected to become a comparative advantage for their country 