At Google, employees are encouraged to place bets on an enterprise prediction exchange, which tries to forecast events based on the money wagered on a particular outcome.

About the academic paper, “Using Prediction Markets to Track Information Flows: Evidence From Google”.

New York Times:

[...] The other crucial finding of the report was that there was a detectible “optimism bias” among Google employees. That is, results that were good for the company tended to be overpriced, particularly for “subjects under the control of Google employees, such as, would a project be completed on time or would a particular office be opened.” [Said Eric Zitzewitz.] This optimism was most evident among new employees, the report found, and it was bound to show up on days when Google stock had climbed. [...]

Google, however, is no ordinary company. As detailed in a footnote, one Google employee, looking to be a profitable trader, wrote the code for an extremely prolific trading robot. As a result, he “was participating in about half of all trades” and made a profit (in Goobles). So the authors had to compensate for these trades. Who knew that someone from Google would try to game the system?

Using Prediction Markets to Track Information Flows: Evidence From Google – (PDF file) – by Bo Cowgill (Google economic analyst), Justin Wolfers (University of Pennsylvania) and Eric Zitzewitz (Dartmouth College)