Darrell Preston of Bloomberg News wrote a great piece comparing the yields on trades of comparably rated corporate and municipal bonds. He highlighted that corporate bonds have a much higher risk of default than municipal bonds but have similar yields. His analysis suggests that risk is not being properly priced if in fact ratings between asset classes are comparable and that municipal issuers are paying interest rates that are too high.

Two years after Moody’s Investors Service and Fitch Ratings changed standards to put municipal credits on the same footing as corporates, California and Illinois are among states that still pay more for debt than similarly or lower-rated corporations, according to data compiled by Bloomberg. Yet Moody’s says companies default at 86 times the municipal rate.

“Taxpayers continue to get a raw deal,” said Tom Dresslar, spokesman for California Treasurer Bill Lockyer, who pressed for the rating changes. “Not much has changed.”

Preston’s article compares the yield for recent trades for the state of California and a private energy producer, which are rated at near-equivalent levels:

When California and A2 rated Idaho Power both sold 30-year debt this month, the utility’s bonds priced 6 basis points lower than California’s … according to data compiled by Bloomberg. The Boise company provides electricity for southern Idaho and eastern Oregon. The state is rated one step higher at A1 and offers tax-exempt securities to provide an incentive to investors to accept a lower yield.