Suppose that Maldonia and Sylvania specialize and open up to international trade, and the terms of trade in the world market are 1 pound of grain for 1 pound of tea. That is, Maldonia is willing to sell Sylvania 1 pound of grain in exchange for 1 pound of tea, and Sylvania is willing to sell Maldonia 1 pound of tea in exchange for 1 pound of grain. The countries decide to exchange 2 million pounds of grain for 2 million pounds of tea.
The following graph shows the same PPF for Maldonia as before, as well as its initial consumption at point A. Use the green line (triangle symbol) to plot the trading possibilities line (TPL) for Maldonia. Then place the black point (plus symbol) on the trading possibilities line to indicate Maldonia’s consumption after specialization and trade.