Yield equivalence is a financial term used to describe the relationship between two different types of investments that produce different yields. It refers to the yield of a taxable bond that would be equivalent to the yield of a tax-exempt bond. Essentially, it is a measure of the yield on a taxable bond that would result in the same after-tax return as an equivalent tax-exempt bond.

Yield equivalence is important to investors because it allows them to compare the yields of different investments on an after-tax basis. For example, an investor may be considering investing in a municipal bond with a tax-exempt yield of 3%, or a taxable corporate bond with a yield of 4%. In order to compare the two investments, the investor would need to calculate the yield equivalence of the tax-exempt bond.

The formula for calculating yield equivalence is as follows:

Yield Equivalence = Tax-Exempt Yield / (1 - Tax Rate)

Where Tax Rate is the investor's marginal tax rate.

For example, if an investor is in the 25% tax bracket and is considering a municipal bond with a tax-exempt yield of 3%, the yield equivalence would be:

Yield Equivalence = 3% / (1 - 0.25) = 4%

This means that a taxable bond with a yield of 4% would provide the same after-tax return as the tax-exempt bond with a yield of 3%.

Yield equivalence is a useful tool for investors who are considering investments in both tax-exempt and taxable securities, as it allows them to compare the after-tax yields of different investments and make informed decisions.