US economist Paul Milgrom was informed that he won the Nobel Economics Prize with a knock on his door, at 2:15 am. When Nobel Prize committee could not reach him, Robert Wilson, who shared the top honours with him, went to Milgrom’s house to share the incredible news. A video of Wilson, 72, ringing his 83-year-old Nobel partner's doorbell and knocking on his door in the middle of the night has been tweeted by Stanford University. Both of them are professors at Stanford and live on the same street. The black and white security camera video shows Wilson and a woman, reportedly his wife, walking to Milgrom's door and ringing the bell. Stanford University said Paul Milgrom's wife, who is in Stockholm, received a notification on her phone when Wilson rang his doorbell. "She got to watch live as Wilson told Milgrom he'd won the #NobelPrize," the university tweeted. Paul Milgrom and Robert Wilson won the Nobel Economics Prize for work on commercial auctions, including for goods and services difficult to sell in traditional ways such as radio frequencies, the Nobel Committee said. The Royal Swedish Academy of Sciences noted that the discoveries by the duo "have benefitted sellers, buyers and taxpayers around the world," it said in a statement.