The Pricing of Tax‐Exempt Bonds and the Miller Hypothesis

TLDR

The Miller hypothesis predicts that the tax‑exempt rate is 52 % of the taxable rate, whereas the institutional demand hypothesis predicts a volatile relationship. This paper tests two competing theories of the relation between tax‑exempt and taxable interest rates. The authors use a random‑intercept model to control for the risk of average interest rates. The results favor the Miller hypothesis, with marginal tax rates close to the predicted 48 %, and the relationship is unaffected by relative demand or supply and remains stable over time.

Abstract

ABSTRACT This paper reports a new test of two competing theories of the relation between tax‐exempt and taxable interest rates. The Miller hypothesis predicts that the tax‐exempt rate is 52 percent of the taxable rate, while the institutional demand hypothesis predicts a volatile relationship. The tests in this paper employ a random intercept model to control for the risk of average interest rates. The results favor the Miller hypothesis. Marginal tax rates are found to be close to Miller's predicted 48 percent. The relationship is not influenced by relative demand or supply and the marginal tax rate appears stable over time.