I was supposed to appear on Comedy Central's The Daily Show last night to promote my new book. But I didn’t because The Daily Show was doing reruns. That’s because the show’s writers have gone on strike. Now, this may look like the kind of strike that used to cripple American industry years ago when big labor was really big. But take another look and you find an issue more closely related to Chinese pirating of American movies and CDs than a traditional labor-management brawl. You see, entertainment is coming to be a larger and larger part of what skilled and creative Americans do for a living. Watch the credits at the end of movies and try counting the names. Add in all the people involved in producing musical recordings, animated computer games, books, magazines, advertising. And the ever expanding numbers doing all this and more on the Internet -- through streaming media, webisodes, downloads. Entertainment is also becoming an even larger portion of America’s exports. Depending on how broadly you define it, about 12 to 15 percent of what we sell to the rest of the world. In short, entertainment is among our most valuable properties. But it’s intangible, weightless. --Robert B. Reich (Ed. Note: This is adapted from Reich's weekly commentary on American Public Radio's Marketplace.)