Larry Summers was president of Harvard University when Mark Zuckerberg packed up for the West Coast. Now it seems that Summers, who most recently served as director of the White House National Economic Council, also has a similar itch.

Summers has signed on as a special adviser with Andreessen Horowitz, the venture capital firm whose portfolio includes Internet superstars like Facebook, Groupon, Twitter and Zynga. It’s a part-time role with long-term incentives tied to investment performance, in which Summers will be expected to advise both the firm and portfolio companies on various economic trends. He may also sit on certain portfolio company boards.

“We wanted to add someone to the team with deep experience thinking about global markets, because all of our companies want to be global,” says firm co-founder Marc Andreessen. “All of our companies also are trying to transform markets, which is something Larry knows a lot about.”

Andreessen and Summers first met this past January, though an introduction by Facebook chief operating officer Sheryl Sandberg. Andreessen is a Facebook director, while Summers hired Sandberg as his chief of staff when serving as U.S. Treasury Secretary under President Clinton.

“She told us that we needed to meet each other, and we both do what Sheryl says,” Andreessen explains. “So we got to talking and learned that Larry was interested in doing a set of things around tech, and one of those was wanting to work with a VC firm.”

Summers will have an exclusive VC firm relationship with Andreessen Horowitz, meaning he will not work with any other venture shop. He is free, however, to advise tech start-ups that have received investment elsewhere. For example, he recently joined the board of mobile payment startup Square, which is not an Andreessen Horowitz portfolio company. Summers also may consult other types of financial institutions on macroeconomic trends.

“I think information technology is the economic story of our time,” Summers says. “People will remember this as the moment of IT revolution, long after they forget about the details of Lehman or AIG or the financial disruption. As an economist, it’s exciting to learn more about that and contribute to it.”

Summers declined to definitively answer whether or not the IT market is in the midst of a bubble, saying that today’s market has different characteristics than the 1990s dotcom boom, but that “whenever people get too happy it’s a good idea to maintain one’s suspicions.”