When Chicago Public Schools announced on June 24 that it would borrow $1 billion to make a $600 million-plus pension payment due June 30 an eerie feeling spread across bond investors and taxpayers alike. It was the same feeling that gripped investors when Moody’s Investors Service downgraded Chicago’s credit rating to junk based almost entirely on the city’s pension problems.

The fear was that elevated pension costs, in cities like Chicago, might push these public entities into insolvency, wiping out much of the holdings of municipal-bond investors. Once a sleepy corner of the municipal bond market — often not even properly reflected on cities’ balance sheets — public pensions have recently turned into the biggest headache for taxpayers and municipal-bond investors, threatening to bring down the finances of U.S. cities and states. FULL REPORT