3. For any level of output, the /S curve shows the value of the real interest rate that clears the goods market. The IS curve slopes downward because higher output leads to more desired saving and, thus, a lower goods-market-clearing real interest rate. For constant output, any change that reduces desired national saving relative to desired investment increases the real interest rate that clears the goods market and shifts the JS curve up and to the right. Equivalently, for constant output, any change that increases the aggregate demand for goods increases the real interest rate that clears the goods market and shifts the /S curve up and to the right.