Munis save governments more than $700 billion in interest.

• Position: News & Numbers

State and local governments would have paid $714 billion in additional interest expenses between 2000 and 2014 without tax-exempt municipal bonds, according to a new white paper issued by GFOA and the International City/County Management Association (ICMA).

Other key findings from the new public policy whitepaper, Municipal Bonds and Infrastructure Development--Past Present and Future, prepared by Justin Marlowe of the University of Washington on behalf of ICMA's Government Affairs and Policy Committee, include:

* Virtually all state and local government capital investment is financed through municipal bonds.

* In 2014, state and local governments invested nearly $400 billion in capital projects, a significant slowdown in spending. Total state and local capital spending has not yet returned to pre-Great Recession totals.

* Approximately 90 percent of state and local capital spending is financed by debt.

* Alternative financing methods, such as pay-as-you-go and public-private partnerships, are effective for some types of capital projects, but are not a robust alternative to traditional tax-exempt municipal bonds.

* There are more than one million municipal bonds in the market today, issued by more than 50,000 units of government. Their total par value is just over $3.6 trillion.

* If the federal tax...