Econ 100 : Explain why an economy's income must equal its expenditure.

1. Explain why an economy's income must equal its expenditure. 

2. Sometimes at the beginning of an economic boom, total employment increases sharply but the unemployment rate does not fall. Why might this occur? 

3. When the economy is at full employment, is the unemployment rate at 0 percent? Why or why not?

4. How would a more generous unemployment insurance system affect the full employment figure