Spending on information technology on the part of U.S. manufacturers is finally starting to pay off in increased productivity. Why now? Have IT investments, growing steadily since the 1970s, suddenly crossed a magic threshhold? HBS Professor Andrew McAfee believes the answer lies neither in magic nor in the growing power of computers themselves. Productivity gains, he writes in this article from the online journal Exec, may have more to do with the evolution of computing from PC “islands” to integrated networks that bridge distances and bring people together.