Final answer:
Poland has a comparative advantage in the production of broccoli and Liechtenstein has a comparative advantage in the production of ale. Poland can gain from specialization and trade by receiving more than 5 kegs of ale for each bushel of broccoli it trades.
Step-by-step explanation:
Comparative advantage is determined by comparing the opportunity costs of producing different goods in two countries. In this case, Poland has a comparative advantage in the production of broccoli because its opportunity cost of producing a bushel of broccoli is lower than Liechtenstein's. Liechtenstein has a comparative advantage in the production of ale because its opportunity cost of producing a bushel of broccoli is higher than Poland's.
By specializing in the production of goods in which they have a comparative advantage, both countries can benefit from trade. Poland should aim to receive more than 5 kegs of ale for each bushel of broccoli it trades, as that is the opportunity cost of producing a bushel of broccoli in Poland. This way, Poland can gain from specialization and trade.