Anyone walking or driving the streets of New York on the way to Mayor Bloomberg’s second inauguration will have a difficult time missing the building boom that is under way in this city. From SoHo to Harlem in Manhattan, from Dumbo to Fourth Avenue in Brooklyn, construction cranes are at work building new apartments to serve what seems like a nearly unlimited supply of people who could afford to live anywhere but choose to live in New York.

It is one of the mayor’s great successes. Our David Lombino reports on this trend at page one, and if words alone don’t adequately tell the story, please have a look elsewhere on our front page today at the photographs of construction sites taken in the city over the past few days.

Mr. Bloomberg has contributed to these trends by rezoning some neighborhoods but most of all by making New York a place where people want to live. He’s done this by working with the district attorneys and the police commissioner to keep crime down to record-low levels, by serving as a dogged and enthusiastic cheerleader touting New York to tourists and world business leaders, and by acting as a patron and supporter of the cultural institutions that, along with Wall Street, help make New York what it is. President Bush deserves some of the credit, too. His tax cuts have helped lift New York’s economy, and his war on the Islamic extremist terrorism has helped prevent another terrorist attack in New York like the one of September 11, 2001.

The construction is good news for the city. And it’s illuminating for how it has happened. For the most part, the risk has been borne by private capital. These aren’t new government housing projects being erected, but rather buildings imagined and developed by private businessmen. The sites in the city where government has taken the lead in development – the rail yards on the West Side of Manhattan, the former World Trade Center site at Ground Zero – are the sites where the least has actually happened.

There is more that Mr. Bloomberg can do in his second term to accelerate the building trend, such as cutting taxes at the top margins (i.e., on the next dollar earned), simplifying the building code, pressing to keep organized crime out of the construction industry, and making sure that city agencies like the landmarks commission and the buildings department serve to speed development rather than impede it. But at the end of four years as mayor and on the eve of his second inauguration, the mayor already has left a substantial legacy in brick, mortar, concrete, glass, and steel.