Its slope IS negative, indicating that the IS curve is generally a curve inclined to the lower right. Generally speaking, in the product market, the combination of income and interest rate on the right side of the IS curve is an unbalanced combination of investment less than savings.

The combination of income and interest rate on the left side of IS curve is an unbalanced combination of investment greater than savings. Only the combination of income and interest rate on the IS curve is the balanced combination of investment and savings.

Economic meaning:

Describe the relationship between total income and interest rate when the product market reaches macro equilibrium, that is, I = S.

The total income is inversely proportional to the interest rate, that is, when the interest rate rises, the total income level tends to decline, and when the interest rate falls, the total income level tends to rise.

Any point on the IS curve means i=s, and any point deviating from the IS curve means that the balance has not been reached.

If a point IS on the right side of the is curve, I < stands for I.

If a point IS on the left of the IS curve, I > means I >; S, that is, the current interest rate level is too low, which leads to the scale of investment greater than the scale of savings, which means that the output in the current period fails to meet the demand, and the supply of products in the market is less than the demand.