If we assume that Farmer Kim is from Korea then the exchanges that take place in the second week reflect trade between countries. Farmer Smith's trade of oranges for apples with Farmer Kim represents US exports of oranges in exchange for imports of apples from Korea. In the previous week Farmer Kim was not present, thus all trade took place domestically. The change from week one to week two corresponds to a country moving from autarky to free trade. The critical point here is that free trade does not improve the well-being of everyone in the economy .
Some individuals lose from trade.
We can characterize the winners and losers in a trade context by noting the relationship of the farmers to the trade pattern. Farmer Smith is an exporter of oranges. Farmer Jones must compete with imports on sales to Smith, thus we call Jones an import competitor. Our conclusion then is that export industries will benefit from free trade while import competing industries will suffer losses from free trade . This result corresponds nicely with observations in the world.