When total utility reaches a maximum, then marginal utility is:

During the time period of 1981-1983 what dramatic world issue happened?

A) political instability, insecure property rights B) stock market crashed C) world wide hyperinflation D) the collapse of the U.S. mortgages market E) A world economic recession caused developing countries to not be able to make payments on foreign loans, in turn causing a universal default.

Which of the following contributed to the increase in steamboat productivity?

(a) Improvements in ship design (b) Better docking stations (c) Increased competition by railroads (d) All of the above