Hooray for Bloomberg News for sniffing out a $3.3 billion corporate tax break which actually is just the tip of an ongoing boondoggle involving ? wait for it ? public transportation. Bloomberg noticed that in recent years some 35 separate leasing agreements have been inked between big banks and public transportation authorities.

The deals work like this: the banks buy millions of dollars in rolling stock, be it trains or buses, and then lease the equipment back to the transit operators. It looks like a win-win. The banks get to write down the value of their forays into public transit against their existing profits, a sweet, sweet deal. Better still, the banks’ actual risk is very low as the lease payments are secured by special-purpose transit taxes in many cases. And the transit ops get new equipment they couldn’t otherwise afford, a “salvation” says a Metropolitan Atlanta Rapid Transit Authority official. However, this is not the total picture.

The Bloomberg report drives home the fact that this wrinkle is a corporate tax break for very profitable companies, which is basically an appeal to fairness. It is unfair for these companies to skirt a tax liability. Could be, but it looks like they are just playing by the rules Congress gave them.

More damning, by far I think, is the revelation that a corporate tax break is the engine for equipping the nation’s transit systems with almost $10 billion in rolling stock since 2001. In other words, absent the break, one which reaches into the pocket of every taxpayer in America, the systems could not afford vital upgrades. Think about that for a second.

We’ve always known that public mass transit systems require subsidies, but the true size of the subsidy may well have been hidden thanks to these backdoor tax incentives. And better not to dwell on the fees that consultants and fixers reap from such deals. Crony capitalism is never pretty despite being the polite term for fascism.

But, hey, the trains run on time, right?