Tax-Equivalent Yield
Tax-Equivalent Yield is the pre-tax return that a taxable instrument must offer to match the after-tax return of a tax-advantaged or tax-exempt instrument, providing a common basis for comparing investments across different tax treatment categories in an investor's specific tax bracket.
In India, several instruments offer tax-exempt or tax-advantaged returns: interest on Public Provident Fund and Sukanya Samriddhi Yojana is tax-free; maturity proceeds from certain life insurance policies may be exempt under Section 10(10D); interest on tax-free bonds issued by government infrastructure companies is exempt from income tax; and capital gains on SGBs at maturity are fully exempt. When comparing these instruments against taxable alternatives like fixed deposits, corporate bonds, or mutual funds, a direct yield comparison is misleading without adjusting for tax.
The tax-equivalent yield formula converts a tax-free yield to its taxable equivalent: Tax-Equivalent Yield = Tax-Free Yield ÷ (1 − Marginal Tax Rate). For an investor in the 30% tax bracket (plus applicable cess making the effective marginal rate approximately 31.2%), a tax-free bond yielding 6% is equivalent to a taxable instrument yielding 6% ÷ (1 − 0.312) = approximately 8.7%. This means any taxable instrument offering less than 8.7% is inferior to the 6% tax-free bond for this investor on an after-tax basis.
The calculation changes depending on the investor's tax bracket. For an investor in the 20% bracket, the same 6% tax-free bond is equivalent to only 7.5% pre-tax. Lower-bracket taxpayers benefit less from tax-free instruments; high-bracket taxpayers benefit disproportionately. This is why tax-free bonds are more attractive to corporate treasuries, high-net-worth individuals, and senior professionals than to individuals in the 5% or 10% tax slabs.
Tax-equivalent yield also applies to long-term capital gains comparisons. Since LTCG on listed equity and equity mutual funds is taxed at only 12.5% beyond Rs 1.25 lakh annually, equity returns have an implicit tax efficiency advantage over fully taxable income instruments at identical gross returns. An equity portfolio expected to return 13% gross with all returns in the form of LTCG effectively yields approximately 11.4% after LTCG tax (ignoring the Rs 1.25 lakh exemption), while a bank fixed deposit at 7.5% yields only 5.2% after tax at the 30% bracket.
For financial planners, tax-equivalent yield is a foundational tool in product selection. It prevents the superficially appealing nominal yield of a taxable FD from crowding out superior after-tax returns available from instruments with more favourable tax treatment.