Explanation:
1) Famous celebrities and the people with lots of money are often seen with workers round them for their household chores/tasks. Although they are paying money for the work they could have done by themselves but if we analyze closely, they are actually taking advantage of the opportunity cost. The time when they were suppose to do the household work, now they are performing other task in that time which will be giving them much greater economic benefit, taking advantage of the concept of opportunity cost. For example, Cristiano Ronaldo can focus on his workout and daily exercise instead of making daily meals for himself, so he should have hired someone to do the meal work for him while he perform his workout which will help him on the field and will earn him much money.
2) Yes, it is possible for 2 countries to benefit from trade as a whole because they can get into an agreement by allowing free trade between the countries, for example, both the countries could agree that all the trade which will be executed between them would be tax free and no duties will be paid on them. This way the trade numbers would increase and industrialization would take place to meet the export/import orders. On the contrary, trading individually can be not so beneficial because there will be no free trade agreements between individuals i.e. no free lunches, that is why it could cost individuals much more than they can make money out of it.
3) One of the main reasons to oppose policies that restrict trade among the nations is that GDP. GDP is a measure of growth in any country, therefore when there will be no trade among countries, it would result in less productions of goods and services which which lead to less industrialization, which then will result to low employment and more unemployment, ultimately resulting in very low growth for any country and since growth is the only way forward for any nation, economists oppose policies that restrict trade among countries/nations.
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