Approximately how many people worldwide face periodic or permanent water shortages?

What factor contributed to the growth of federal bureaucracy during the twentieth century?

a. the passage of the Hatch Act in 1939 b. the elimination of the spoils system at the turn of the century c. increased demands upon government during the Great Depression d. the creation of new congressional powers during World War II

Players A and B have PD preferences. Assume the following payoffs for player A: T = 300, P = 10, R = 100. The discount factor ? = 0.5. Which of the following outcomes will we observe if they use the grim trigger strategy?

a. Player A will cooperate, and player B will respond by cooperating. b. Player A will defect, and player B will respond by defecting. c. Player A will defect one period and then resume cooperation in response to cooperation by player B. d. Player A will cooperate in the beginning but then defect, and player B will always cooperate