Public finance involves the taxing and spending activities of government. It focuses on the microeconomic functions of government and examines taxes and spending. Government ideology can view the community or individual as most important. In the US, the federal government has more spending flexibility than states. Government spending has increased significantly as a percentage of GDP from 1929 to 2001. Major items of federal spending have shifted from defense to entitlements like Social Security and Medicare. Revenues mainly come from individual income taxes, payroll taxes, and corporate taxes at the federal level and property, sales, and income taxes at the state and local levels.