I need help with these homework questions. Please be elaborate in your response, thanks.

Questions:

1. What is the difference between government expenditures and government purchases? How do the two variables differ in terms of their effect on GDP?

2. Crowding out reduces the degree to which a change in government purchases influences the level of economic activity. Is it a form of automatic stabilizer?

3. Why is it important to try to determine the size of the fiscal policy multiplier?