An agent has rational preferences if her preferences fulfill two properties, that they are complete and that they are also transitive.
Beggar thy neighbor policy is an economic policy which aims to boost the economy of a country, while worsening the economic conditions for another country.
Autarky refers to the state where the country has no trade with any other country. It is a closed economy.
Usually, goods are categorized into three different groups, which are: normal goods, inferior goods and Giffen goods.