What does the term "marginal" mean in economics?

When one compares per-capital output growth rates among countries

A) one needs to correct the data to account for departures from purchasing power parity. B) such corrections are often not necessary. C) such corrections are sometimes necessary. D) the evidence whether such corrections are necessary are vague. E) such corrections are not necessary.

Assume that foreign capital flows from a nation increase due to political uncertainly and increased risk. If the nation has highly mobile international capital markets and a fixed exchange rate system, what happens to the real risk-free interest rate and GDP Price Index in the context of the Three-Sector-Model? a. The real risk-free interest rate rises and GDP Price Index rises

b. The real risk-free interest rate falls and GDP Price Index falls. c. The real risk-free interest rate rises and GDP Price Index falls. d. The real risk-free interest rate and GDP Price Index remain the same. e. There is not enough information to determine what happens to these two macroeconomic variables.