If consumer confidence falls at the same time as tax rates on corporate profits decrease then what can we say about changes in interest rates and the level of investment in the economy? Savings supply will decrease and investment demand will increase so rates will rise but we can't say for sure what will happen to investment. Rates will rise and investment will increase. Rates will fall and investment will decrease. Savings supply increases and investment demand increases at the same time so we can't say for sure what will happen to rates but we do know that investment will increase