Municipal Bonds: the case for inclusion in Asian insurers' portfolios

Municipal Bonds: the case for inclusion in Asian insurers' portfolios
Key takeaways
Diversification benefits

US municipal bonds can provide a source of diversification within insurers’ existing credit portfolios. 

Attractive yields

Relative value compared to US corporate bonds.

Easy access

US municipal bonds provide access to US infrastructure debt in a publicly available form (revenue bonds).

Charles Moussier, Tim O’Reilly and Tim Spitz introduce the two main types of US municipal bonds and explain why insurers may find them worth including in their portfolios.

What are US municipal bonds?

Municipal bonds have played a vital role in building America’s infrastructure. They were a major source of financing for canals, roads, and railroads during the country’s westward expansion in the 1800s, and today, they fund a wide range of state and local infrastructure projects, including schools, hospitals, universities, airports, bridges, highways and water and sewer systems.

Municipal bonds are issued by US state and local governments (municipalities), eligible not-for-profit corporations and territories and possessions of the US (for example, American Samoa, Guam, the Northern Mariana Islands, Puerto Rico, and the US Virgin Islands). When an investor purchases a municipal bond, he or she is lending money to finance a myriad of public projects.

Traditionally, for US domestic investors, municipal bond interest payments are exempt from federal income taxes, and sometimes state income taxes.

Tax features

For investors who do not pay taxes in the US, these tax features might be considered a drawback rather than an advantage, as nominal yields are driven down by investors who can utilise tax deductions.

This is why foreign investors usually focus on the taxable portion of the municipal market. Taxable municipal bonds offer higher risk-adjusted yields comparable to those available on other taxable issues, such as corporate bonds.

The taxable municipal bond market represents over USD760 billion of the total municipal market, with over 3,000 issuers (approximately 21% of the overall municipal bond market).

Issuers may choose to issue a taxable municipal bond for a variety of reasons, including access to a broader investor base, the flexible use of proceeds and the fact that the financed activity is not considered tax-exempt.

Issuers of municipal bonds also have the ability to issue debt using corporate cusips. This has created a sub-class of municipal bonds that use a corporate cusip identifier. The aim is to take advantage of the greater liquidity and diverse investor base offered by the corporate market. Typically, municipal issuers access the corporate bond market to issue longer-dated structures that are attractive to liability-driven investors.

Potential attractions for investors

As well as the tax features mentioned above, US municipal bonds may be worth consideration as a source of long-dated, high credit quality fixed income and a source of potential diversification within existing credit portfolios.

They also provide access to US infrastructure debt in a publicly available form (revenue bonds) and offer potentially higher yields than similarly rated public credit, with a history of lower default rates and higher recovery rates.

Two types of municipal bonds

Municipal bonds generally fall into one of two categories: general obligation bonds or revenue bonds. The primary distinction between the two is the source of revenue that secures the bonds.

General obligation bonds at the state level are secured by the state government’s pledge to use all legally available resources to repay the bond.

Examples of issuers of general obligation bonds include states, cities, counties, and school districts.

Revenue bonds are secured by a specific source of revenue earmarked exclusively for repayment of the revenue bond. Water and sewer authorities, electric utilities, airports, toll roads, hospitals, universities, and other not-for-profit entities typically issue these bonds to finance infrastructure projects.

Favourable liability-matching features

There are many features of typical municipal bonds that make them an instrument worthy of consideration for matching insurers’ long-term liabilities. Key features when compared to global corporate bonds include lower default rates, stability of ratings (Figure 1), higher recovery rates and predictable long-term income.

Figure 1: One-year drift, US municipal issuers vs. global corporate issuers, 1970-2022

Source: Moody's Investors Service

Most state and local governments are highly rated, whereas corporate credits tend to have lower average ratings. The median rating of municipal issuers is Aa3, compared to Baa3 for global corporates.

Accordingly, it is not surprising that municipal default rates have been extremely low, especially when compared to global default rates. The global corporate investment grade default rate is more than 24 times higher than the municipal investment grade default rate. The 10-year average cumulative default rate for high yield global corporate bonds is more than four times higher than the high-yield municipal bond default rate (Figure 2). 

Figure 2: US municipal versus global corporate issuers’ default rates

  Municipal Bonds  Corporate Bonds 




























All Rated  0.15    10.72 

Source: Moody’s Investor Service, 19 July 2023: US Municipal Bond Defaults and Recoveries, 1970-2022.

Past performance is not a guide to future returns.

Figure 3 looks at the universe of taxable municipal bonds comparing outstanding issues with municipal cusips to those with corporate cusips. The maturity structure of both sets of bonds is tilted toward the longer end, with the bias for longer-maturity structures stronger in corporate cusip securities. This shows the availability of longer-maturity bonds to match longer-dated liabilities, for example, those of life insurers.

In addition, all taxable municipal bonds are usually noncallable, which is favourable for liability-matching purposes.

Figure 3: Maturity structure of taxable municipal bonds - municipal cusips versus corporate cusips

Source: Bloomberg, JP Morgan, 29 February 2024. Fixed and zero coupon only. Notes excluded. 

Solvency capital charge considerations

Asia-based insurers have been or are increasingly subject to risk-based capital regimes. Broadly, the capital requirement of a bond or loan is calculated based on interest rate, credit spread, and currency risks.

In simple terms, the credit spread risk assigns a capital charge based on the duration, rating (credit quality step) and nature of a bond (for example, sovereign bonds may be exempted from credit spread shocks if they are rated above a certain threshold, bonds issued by multilateral agencies may incur a lower charge compared to generic corporates, etc.).

Given the impact of a bond’s credit rating on the calculation of the credit spread risk charge, US municipals’ high-quality profile may be attractive to insurers. This may be especially true for insurers searching for “cheap” sources of duration to match longer-dated liabilities.

In addition, US taxable municipal bonds typically pay higher yields than equivalently rated public credit or corporate bonds. This leads to a higher expected capital-adjusted return compared to other types of bonds, even if US taxable municipal bonds are treated as US dollar corporate bonds under the regulatory regimes.

Under Solvency II, in 2016, EIOPA (European Insurance and Occupational Pensions Authority) updated the spread risk module to include a new set of capital requirements specifically for infrastructure investment (both equity and debt). When compared to similarly rated corporate bonds, the infrastructure debt sector requires approximately 30% less capital to be held by the insurer. Identifying municipal bonds meeting the requirements could therefore be favourable.

It remains to be seen whether regulators in Asia may take the same approach in future amendments to their rules and guidelines. Nevertheless, as has been illustrated above, municipal bonds can still be a good fit within insurers’ portfolios in the region.

Why Invesco

Invesco is among the top five municipal bond managers by assets. Our management philosophy is based on the belief that creating long-term value through comprehensive, forward-looking research is the key to providing clients with consistent and successful investment strategies. The Invesco municipal bond team of dedicated investment professionals has more than 20 years of industry experience and manages more than $65 billion1 in municipal assets.

Finding exceptional investment opportunities requires exceptional research. Our team of dedicated research analysts performs their own hands-on credit analysis, reviewing and internally rating each and every credit owned. We believe this attention to detail combined with our sizes as one of the leading managers of municipal bonds allows us to maximize risk-adjusted returns.

Investment risks

  • The value of investments and any income will fluctuate (this may partly be the result of exchange rate fluctuations) and investors may not get back the full amount invested.

    Municipal securities are subject to the risk that legislative or economic conditions could affect an issuer’s ability to make payments of principal and/or interest.

    All fixed income securities are subject to two types of risk: credit risk and interest rate risk. Credit risk refers to the possibility that the issuer of a security will be unable to make interest payments and/or repay the principal on its debt. Interest rate risk refers to the risk that bond prices generally fall as interest rates rise and vice versa.

    Municipal bonds are issued by state and local government agencies to finance public projects and services. They typically pay interest that is a tax in their state of issuance. Because of their tax benefits, municipal bonds usually offer lower pre-tax yields than similar taxable bonds.


  • 1

    Data as of March 31, 2024

Related insights