When there are a few empty seats on an airline flight, the marginal cost of adding extra passengers to occupy those seats?

What is free trade? a. trade that is not subject to taxes or fees b. trade that governments do not interfere with c. trade with a high level of government regulation d. trade between states in the u. s. b

Stocks a, b, and c are similar in some respects: each has an expected return of 10% and a standard deviation of 25%. stocks a and b have returns that are independent of one another; i. e., their correlation coefficient, r, equals zero. stocks a and c have returns that are negatively correlated with one another; i. e., r is less than 0. portfolio ab is a portfolio with half of its money invested in stock a and half in stock b. portfolio ac is a portfolio with half of its money invested in stock a and half invested in stock c. which of the following statements is correct? a. portfolio ab has a standard deviation that is greater than 25%.b. portfolio ac has an expected return that is less than 10%.c. portfolio ac has a standard deviation that is less than 25%.d. portfolio ab has a standard deviation that is equal to 25%.e. portfolio ac has an expected return that is greater than 25%.

What is one counter argument to the premise that the wealth gap is a serious problem which needs to be addressed?