Given the products below and the events that affect them, indicate what happens to demand and/or supply, and the equilibrium price and quantity in a competitive market. Identify the determinant of demand and/or supply that causes the shift. Explain your reasoning fully in each case.
(a) Calculators. More schools require students to buy and use calculators; improved productivity shortens the time it takes to make calculators.
(b) Gasoline. Oil production declines due to a crisis in the Middle East; people take more car vacations and drive more.
(c) New homes. The average incomes fall as the economy moves into recession; the productivity of home construction workers and builders increases.
(d) Tobacco. The government cut its subsidy to tobacco farmers; more people quit smoking.