John Cassidy, a writer for the New Yorker magazine, wrote a blog post arguing against New York City's having installed bike lanes. Cassidy complained that the bike lanes had eliminated traffic lanes on some streets as well as some on-street parking. A writer for the Economist magazine disputed Cassidy's argument with the following comment: "I hate to belabour the point, but driving, as it turns out, is associated with a number of negative externalities." What externalities are associated with driving? How do these externalities affect the debate over whether big cities should install more bike lanes? Sources: John Cassidy, "Battle of the Bike Lanes," New Yorker, March 8, 2011; and "The World Is His Parking Spot," Economist, March 9, 2011.