The first thing the deputy mayor for economic development, Robert Lieber, wants known is that he does not have a lot of time left.

At any given moment Mr. Lieber — who, rest assured, at age 53 appears to be in fine health — may rattle off the number of days, minutes, even seconds he has left in office.

“There is a tendency in a bureaucracy where money is not the end game where you can have a lot of process,” said the former managing director for private equity at Lehman Brothers, who succeeded Daniel Doctoroff as the city’s economic tsar three months ago. Mr. Lieber is now spearheading a number of huge development projects for the city and is responsible for keeping New York’s economic engine purring at a time of growing uncertainty.

“You know that expression ‘We really had a great meeting’? I hate that expression. What is a great meeting? What did you accomplish? What are you going to do next? ‘Well, we are going to have another meeting.’ It’s like a one-legged duck: You go around in circles but you don’t make any progress,” he said in the first of two interviews with The New York Sun. “I can’t afford to just have meetings,” he said.

With the threat of recession looming, Mr. Lieber’s sense of urgency seems understandable. In the span of 42 days — the time elapsed between the two interviews — New York’s economy received a series of shocks. The co-chairman of the Empire State Development Corporation and one of Mr. Lieber’s contemporaries at the state level, Patrick Foye, resigned in the wake of the Spitzer sex scandal. Executives from Madison Square Garden signaled that they will move forward with a renovation plan for the arena that all but ends a $14 billion proposal to remake Penn Station and the area surrounding it. The investment bank Bear Sterns collapsed, suggesting further layoffs on Wall Street. The Related Companies’ proposed redevelopment of Pier 40 became the latest in a string of projects to stall or fall apart. And business owners around the Willets Point section of Queens filed a lawsuit against the city, accusing the Bloomberg administration of willingly neglecting the area to allow it to fall into disrepair to depress property values, call it urban blight, and seize the land through eminent domain.

In the first interview, Mr. Lieber outlined his approach to being deputy mayor for economic development and how his strategy differs from that of Mr. Doctoroff. He also laid out his list of priorities, at the top of which is the Willets Point redevelopment, a $3 billion plan to turn a 75-acre site near Shea Stadium in Queens into a retail and entertainment facility.

“We have a very extensive list of projects, and I think that is a hallmark of my predecessor, to make everything a priority,” he said. “But we need to be a little more calculating about what we are going to focus on, because you are not going to be remembered for completing 40% of 100 projects, you are going to be remembered for the 40 projects that you did complete. It is important that we identify those projects, look at all the projects, and establish an appropriate critical path timeline.” The differences between Mr. Lieber and Mr. Doctoroff are subtle, more style than substance. Mr. Doctoroff had the luxury of being in office for six years, and was considered more of a classic City Hall operator who had his irons in a number of fires.

During his tenure, which was marked by a period of unprecedented economic growth and prosperity, Mr. Doctoroff was responsible for rezoning dozens of city neighborhoods and reviving sections of the Bronx, Brooklyn, and Queens. But Mr. Doctoroff was criticized for coming up short on two signature projects, a bid for the 2012 Olympics and a proposal to build a giant football stadium on the far West Side of Manhattan.

“Dan had time to create an overall picture of where he thinks the city should go, and he just wanted to get there. It’s kind of hard to figure out where Robert is going to go,” Council Member Melinda Katz, who as chairwoman of the City Council’s Land Use Committee has worked closely with both men, said in an interview. “Robert has a background of being very straightforward and to the point, which is a good quality in a person you are negotiating with. He is a step-by-step guy.”

Also easy to see is the differing economic environments under which the men were expected to produce.

“The credit market collapse has certainly brought a whole other dimension to the game,” Mr. Lieber said.

Mr. Lieber often notes that New York’s economy has been resilient enough to weather previous recessions and points to the growth of tourism, fashion, and technology as proof of the city’s diversified economy. He said that while the city is presently suffering through a credit crisis, it has not seen big changes in unemployment. He takes the long view on development projects, saying projects like Willets Point and the Governors Island redevelopment take time and that “hiccups” are part of the process. He is also convinced that the city will be able to lure Madison Square Garden back to the table for the redevelopment of Penn Station.

But he added, “If the whole world goes into a depression, is it going to affect our economy? Yes. But we don’t think that is on the horizon, and we continue to work to try to diversify our economy here.”

Mr. Lieber welcomed the accession of Governor Paterson and said the ESDC under the Spitzer administration “created confusion.”

“I think the former governor wanted to be very closely involved in minute details of a project, which is really good on one hand but provides complications to the process that slows things down on the other hand,” he said.

If the redevelopment of Willets Point ultimately emerges as Mr. Lieber’s legacy project, a second obstacle will be local Council Member Hiram Monserrate, who opposes the plan and whose support may prove critical. Mr. Monserrate described his dealings with Mr. Lieber as “professional,” but he said he was concerned about what he called Mr. Lieber’s pro-development tilt.

“This is a pro-development administration and they are very friendly to developers, and Mr. Lieber’s appointment is consistent with that, which makes it that much more important for the council to counterbalance and to ensure that the concerns as they relate to working people — prevailing wages, affordable housing, and other social issues — are dealt with at the bargaining table,” Mr. Monserrate said.

Mr. Lieber said he is sympathetic to business owners in Willets Point who feel neglected, but said the point of the redevelopment is to improve the area.

The city recently extended the deadline for submission of final bids for the development to June 15 from May 5.

At the end of the second interview, Mr. Lieber recalled that Babe Ruth is known for his 714 home runs — not his 1,330 strikeouts.

“No one remembers you for the things you fail at,” he said. “Only the things that you get done.”