Part of the 2009 stimulus package ($93 billion)

was paid out in the form of tax credits.

However, even though interest rates did not change significantly during that year, aggregate output did not increase. Using the parameters from the numerical example on page 239,

a) calculate the decrease in autonomous consumption expenditure necessary to offset the effect of the $93 billion tax cut.

b) show your answer graphically (show the effects of the tax cut and the decrease in autonomous consumption expenditure).