Market Efficiency: The Efficiency of Online Sportsbooks in the NHL Betting Market

We investigate the efficiency of various legalized, online sportsbooks in the National Hockey League betting market. Empirical research, across several sports, find that betting markets tend to be efficient. However, there have been recognized inefficiencies in several sports, but over time, these inefficiencies tend to dissipate. Sports betting has increased dramatically as betting has been legalized in an increasing number of states. With the increase in the number of states legalizing online sports betting, the increase in the availability of online sports books, and the growing interest and participation in online sports betting, the question of interest becomes are these various online sportsbooks efficient in the online betting market. We test the efficiency of twelve different online sportsbooks that have posted odds for NHL hockey games starting with the 2018-2019 season through the 2021-2022 season. Out of the twelve sportsbooks that we tested, we found that only three sportsbooks were inefficient at the 10% significance level over this period. We also find that the results are dominated by the 2021-2022 regular season.本研究旨在探究美国国家冰球联盟（National Hockey League，NHL）博彩市场中多家合规在线体育博彩平台的市场效率。多项针对不同体育项目的实证研究显示，体育博彩市场整体趋向于有效市场状态。不过，部分体育项目的博彩市场已被证实存在效率缺失现象，但此类低效性往往会随时间推移逐渐消散。随着越来越多的州将体育博彩合法化，体育博彩行业规模呈爆发式增长。伴随将在线体育博彩合法化的州数量、在线体育博彩平台供给量持续攀升，以及公众对在线体育博彩的兴趣与参与度不断提升，当前亟待解答的核心问题为：各类在线体育博彩平台在在线博彩市场中是否具备市场效率。本研究针对2018-2019赛季至2021-2022赛季期间，为NHL赛事开出赔率的12家不同在线体育博彩平台的市场效率展开检验。检验结果显示，在所测试的12家博彩平台中，仅有3家在10%的显著性水平下呈现出效率缺失状态。同时本研究发现，整体检验结果主要由2021-2022赛季的常规赛数据主导。