Both of these statements are true. The law of comparative advantage implies that trading partners can be made better off if each specializes in the production of goods for which it is a low opportunity cost producer and trades for those goods for which it is a high opportunity cost producer. This situation will lead to a minimization of costs and a maximization of output. There must be differences in the relative prices of products across countries in order for this comparative advantage to be realized.
This is because the price of a good reflects the production costs. If all production costs were equal across countries then there would be no incentive to trade since each country can produce with equal efficiency.

The Dividends account does affect retained earnings because it is closed to the Retained
Earnings account during the closing process. The Sales Revenue and Rent Expense accounts also affect retained earnings because they are closed to the Income Summary account, which is closed to the
Retained Earnings account. The Common Stock account does not affect retained earnings. Common stock represents stockholders' claims arising from their investment in the company. Retained earnings represent stockholders' claims arising from profitable operations.

Because Keynesian equilibrium is dependent on equality between planned aggregate expenditures and output, it need not take place at full employment. An economy in Keynesian equilibrium has no tendency for output to change even if output is well below full employment capacity.

Since the purchase of a bond by a French company decreases the supply of U.S. dollars on the foreign exchange market, this transaction is accounted for as a credit on the U.S. balance of payments account.

Just because Glassia uses the prospect of research coverage as an inducement for investment banking business does not imply that the research reports will not be objective.