The marginal propensity to save plus the marginal propensity to consume always equals 1

The main reason why income per capita and income per worker varies across countries is because ________

A) prices vary across countries B) currencies vary across countries C) productivity varies across countries D) interest rates vary across countries

Consider a market in which there is an external benefit. The inefficient market equilibrium is such that

A) too little output is produced. B) too much output is produced. C) price is too high. D) marginal social cost is greater than marginal social benefit.