The first question to ask Jay Walder, named by Gov. Paterson yesterday to run the MTA, is this: Why the hell do you even want the job?

A 12-year MTA veteran, Walder was finance and planning chief at the agency that oversees the London subway system, and he helped put together that city’s bid for the 2012 Olympics.

So, all things being equal, he’s probably up to the MTA gig.

But all things are not equal in post-Eliot Spitzer New York. The MTA is broke, government in general is in chaos and Paterson has shown neither the appetite nor the ability to provide political backup of the sort necessary to keep the MTA functional until an elected governor takes office on Jan. 1, 2011.

Why Paterson felt compelled to dismiss the relatively capable Lee Sander as MTA boss is still a mystery. Then he waited weeks to name a successor — apparently without touching base with the relevant state senators.

Confirming Walder, a key senator said yesterday, “isn’t the most critical issue we’re facing at the moment.”

Oh, well. Jay Walder hasn’t even taken the oath of office, and he’s a lame duck.

Best of luck to you, sir.