Harvard economist Ed Glaeser, an expert on city economies, argues that communications technology and face-to-face interactions are complements like salt and pepper, rather than substitutes like butter and margarine. Paradoxically, your cell phone, email, and Facebook networks are making it more attractive to meet people in the flesh....

One day, perhaps, virtual communication will become so good we'll no longer feel the need to shake hands with a new collaborator or brainstorm in the same room. But for now, the world seems to be changing in a way that actually demands more meetings. Business is more innovative, and its processes more complex. That demands tacit knowledge, collaboration, and trust — all things that seem to follow best from person-to-person meetings. "Ideas are more important than ever," Glaeser says, "and the most important ideas are communicated face-to-face."

Tim Harford. How Email Brings You Closer to the Guy in the Next Cubicle.