Charts: Municipal Bond to US Treasury Yield Ratio

I’ve been investing in tax-exempt municipal bonds for a few years now. I made the change due to a combination of reasons. For one thing, I started running out of room in my tax-deferred accounts for US Treasury bonds, TIPS bonds, and REITs. Second, I believe that buying muni bonds through a Vanguard actively-managed mutual fund gives me a diversified mix of high-quality bonds. Third, the effective after-tax yields on muni bonds can be very attractive when compared to US Treasury bond yields. In many time periods, muni yields have been as high as Treasury yields, even before any tax considerations. This was very rare pre-2008 financial crisis, with the historical average being a 80% ratio.

Here are a few charts that track the relationship between the yields on US Treasury and Investment-grade municipal bonds. Notice that the ratio of Muni-to-Treasury has kept close to 100% in the last few years. I’ve tried to dig up enough to cover a continuous timeline, but let me know if you have a better graph.

Source: Wealthmanagement.com

Source: Financial-Planning.com

Source: ValueWalk.com

Although it can be tempting to use these charts as timing tools, I try to focus on the overall picture. Due to the tax-exempt advantage, I am happy as long as the muni rates are roughly the same as Treasury rates.

As of September 9, 2015, the SEC yield of Vanguard Intermediate-Term Tax-Exempt Investors Shares (VWITX) was 1.78% while the SEC yield of Vanguard Intermediate-Term Treasury Investor Shares (VFITX) was 1.43%. Both are hardly exciting and the muni fund is considered a little more risky (how much riskier is quite difficult to quantify), but for my own portfolio I think the higher yield is worth it especially considering the muni interest is exempt from federal income taxes.

Muni bonds are a somewhat different from other asset classes because they are owned mostly by individuals as opposed to institutions. Based on Morningstar investor returns, us individuals haven’t shown any superior skill at market timing their buys.

However, the performance gap is similar to that of the Vanguard Treasury fund of similar duration. So perhaps that gap is just due to the effect of natural cashflow timing (i.e. regular investments over time) rather than failed attempts at chasing performance.