Last night New York City saw its first mayoral debate between Bill de Blasio and Joe Lhota. Despite being the debut battle between the two candidates, it felt like a rerun. There was half-hearted regurgitation of campaign platforms and some pro forma "sparring," the type that gets political reporters re-tweets but has you reaching for that Ethan Hawke shoot 'em up remake your roommate forgot to return to the Redbox. However, the debate did feature a substantive discussion on affordable housing. Since you were too busy counting Brian Dennehy's "Dammits," here's where your next mayor stands on one of the most important issues of our time.

The Public Advocate was chided for not forcing the issue of affordable housing with Atlantic Yards developer Bruce Ratner (who happens to be a campaign supporter). "I did consistently advocate for it," de Blasio said. "I understand there were lawsuits, but I did push hard for affordability there and in many places in Brooklyn and around the city."

"While de Blasio has, when pressed, expressed disappointment with Atlantic Yards, it's inaccurate to say he [sic] 'pushing the [Atlantic Yards] developer [Forest City Ratner] to deliver on his promise for more affordable housing,' " Atlantic Yards watchdog Norman Oder wrote.

The discussion then moved to the subject of affordable housing in general. De Blasio's plan is "for 200,000 units of new or affordable housing and preserved affordable housing over the next ten years."

Lhota's plan calls for "150,000 new units over the next four years," but with a caveat.

"I don't believe in mandatory inclusionary zoning, I don't think that will work," Lhtoa said, referring to the practice of requiring developers to build a certain number of affordable housing units for developments of a certain size. "I think it's a violation of the Constitution. The Supreme Court has spoken about this, saying it's a taking."

Not exactly. While preserving a neighborhood's diversity—economic or otherwise— in the face of gentrification is not a "constitutionally bulletproof" argument, Harvard professor, attorney, and urban planning expert Jerold Kayden asserts [PDF] that legally, "it is fair to ask the developer to match the community’s diversity goal."

Mandatory inclusionary zoning programs [PDF] are more successful than voluntary programs, but require complex legislative mechanisms of enforcement as well as "density bonuses" and different options and incentives for developers.

Mayor Bloomberg's policy has been voluntary inclusionary zoning, which has yielded mixed results (at best).

It seemed that the debate was grounded on the practice citywide, regardless of whether the land was previously owned by the City or a state agency, as it was in the Atlantic Yards scenario (Kayden writes that this requires "carefully reasoned rationales, clearly stated assumptions, and solidly prepared economic analyses," on the part of the city trying to enforce mandatory inclusionary zoning laws). But de Blasio shifted it to land owned by the government.

"It's absolutely legal and appropriate…It's simply the government of New York City saying to developers, if you want the right to make a very tidy profit on land that we're going to open up for development that you didn't have access to before or couldn't build as high on," de Blasio said. "We're demanding affordable housing back in the name of the people…Of course we have that power."

Lhota then cautiously agreed: "There's a middle ground that needs to be taken. If you ask anything from the City of New York you will be required, when I'm mayor, to build affordable housing."

Later, Lhota said he'd keep Ray Kelly on as police commissioner, de Blasio admitted to liking sports teams from Boston, and no one mentioned that there were twelve other people running for mayor.