(2) In 2020, to counter the economic fallout of the COVID-19 pandemic, the US government took several economic stimulus measures. For example, the $2.2 trillion Coronavirus Aid, Relief, and Economic Security Act (CARES Act) was passed in March 2020. After economic stimulus packages, total federal spending spiked to $6.6 trillion in 2020. Fiscal Year 2019 2020 Federal Spending $4.4 trillion $6.6 trillion % of the US GDP 21.0% $31.3% How real interest rate (r) is determined in a closed economy? How the increase of federal spending would affect total national savings ($), real interest rate, and investment? Based on information given, use a proper supply-demand diagram to depict the change of real interest rate of the US in 2020. Note: Here we still assume we are in a closed economy. 6