Explain short-run and long-run effects on the US GDP and the price level for the following events. Assume that policymakers take no action.
1. Technological breakthroughs increase productivity of American workers.
2. Recession in Eurozone countries causes them buy less of the US exports.
3. Federal government increase spending on public school system.
4. S&P 500 stock index falls for several weeks which affects consumers' wealth.