MPP is the additional output that results from a one-unit increase in use of the input

According to the gravity model, a characteristic that tends to affect the probability of trade existing between any two countries is

A) their cultural affinity. B) the average weight/value of their traded goods. C) their colonial-historical ties. D) the distance between them. E) the number of different product varieties produced by their industries.

Debt service refers to:

A. how much debt a country incurs each year. B. the fraction of a country's debt that becomes due each year. C. the interest rate a country pays on its debt. D. the interest payments a country makes on its debt each year.