Machine-Learning Wizards Vie for Zillow's $1 Million Prize

In 1714, the British Parliament passed the Longitude Act, which offered serious money to anyone who could devise a practical method to measure longitude at sea. While the determination of longitude might seem a trivial thing in today's world of smartphones and GPS satellites, at the time it was an immense technical challenge. It took many years, but the strategy worked, leading to the development of the marine chronometer, a handheld mechanical marvel that undoubtedly saved the lives of countless sailors. Prizes have, of course, since been used to spur innovation in many other spheres. "These were typically offered by governments," says Josh Lerner of the Harvard Business School, who has studied the effectiveness of such prizes.