We consider the design of forecasting competitions in which multiple forecasters make predictions about one or more independent events and compete for a single prize. We have two objectives: (1) to award the prize to the most accurate forecaster, and (2) to incentivize forecasters to report truthfully, so that forecasts are informative and forecasters need not spend any cognitive effort strategizing about reports. Proper scoring rules incentivize truthful reporting if all forecasters are paid according to their scores. However, incentives become distorted if only the best-scoring forecaster wins a prize, since forecasters can often increase their probability of having the highest score by reporting extreme beliefs. Even if forecasters do report truthfully, awarding the prize to the forecaster with highest score does not guarantee that high-accuracy forecasters are likely to win; in extreme cases, it can result in a perfect forecaster having zero probability of winning. In this paper, we introduce a truthful forecaster selection mechanism. We lower-bound the probability that our mechanism selects the most accurate forecaster, and give rates for how quickly this bound approaches 1 as the number of events grows. Our techniques can be generalized to the related problems of outputting a ranking over forecasters and hiring a forecaster with high accuracy on future events.

PwC is on the cusp of launching a robo-economist that could make the company the "most accurate" economic forecaster on the market. The professional services firm has developed a form of artificial intelligence (AI) with a 92% strike rate when it comes to predicting the result of UK gross domestic product (GDP). It discovered the AI's "incredible accuracy" after testing to see if the machine could pinpoint historic GDP results without knowing the outcome. But while Jonathan Gillham, PwC's director of economics, joked that the AI had already started to supersede his job, the firm said there were no plans to replace staff with automation and the program would work alongside human economists. He said: " We have been using an AI technique to forecast the UK economy and we will be launching that (...) in July. "Each quarter, the Office for National Statistics publishes its estimate for GDP and we have been able to use an AI technology base to get that right 92% of the time for the last five years.