Question

improvements in the health of the average american caused the u.s. production possibilities frontier to shift out primarily by
a. accelerating technological progress.
b. increasing the countrys effective workforce.
c. raising the capital - labor ratio.
d. encouraging more consumption.

Explanation:

When the health of the average American improves, workers are more productive and less likely to be absent due to illness. This effectively increases the number of workers available to produce goods and services. A production - possibilities frontier (PPF) shifts outward when there is an increase in resources (in this case, a more effective workforce), technological progress (not directly related to health improvement in this context), or an increase in capital. Option A (accelerating technological progress) is not the main factor here as the question is about health. Option C (raising the capital - labor ratio) would require an increase in capital relative to labor, which is not indicated by health improvement. Option D (encouraging more consumption) affects the demand side and not the production capacity (PPF is about production capacity).

Answer:

B. increasing the country's effective workforce.