Louise Mozingo writes about suburban office park sprawl and concludes that “All three steps — a halt to agricultural land conversion, connecting dispersed employment centers with alternative transit, and encouraging downtown development — are needed to create renewed, civic-minded corporate workplaces and, in the process, move toward sustainable cities.” I’m very sympathetic to the spirit of this, but the phrasing implies that real estate developers have some kind of inexplicable aversion to building downtown transit accessible offices and need to be strong-armed into doing it. The reality in most of America’s largest cities is the reverse. I’m in New York City right now where there’s one cluster of skyscrapers in Lower Manhattan and another cluster in Midtown but then a huge gap from roughly Chambers Street into the 30s. That’s not all filled in with additional giant buildings because you’re not allowed to build them there. In Washington, DC the tallest office building is just 210 feet and you generally can’t build anything bigger than 160-180 feet. I’m not as familiar with the rules elsewhere, but if you look at the rents around, say, the Harvard Square T station and then look at the size of the buildings there’s clearly a supply restriction happening. When you build good transit connections and allow very dense construction then you wind up with lots of transit-accessible centrally located jobs. But if you don’t, then naturally firms will start searching far afield for space they can afford.