Classify the following as microeconomics or macroeconomics and provide a justification for your choice.

(i) The effect of changes in household saving rates on the growth rate of national income.

(ii) The effect of rising oil prices on employment in the airline industry.

(iii) A comparison of alternative tax policies and their respective impacts on the rate of the nation’s economic growth.

(iv)Changes in the nation’s unemployment rate over short periods of time.