近年來，隨著網路的普及，中國網路投資平台興起，股吧投資專家在論壇發表的投資意見備受投資人關注，對分析師而言形成一股競爭壓力。若股吧投資專家與分析師追蹤同一間公司，分析師可能有誘因為維護聲譽而提升盈餘預測準確度。本研究目的係檢視股吧投資專家首次加入有否影響到不同能力分析師之盈餘預測偏頗及盈餘預測錯誤。
本研究將分析師盈餘預測偏頗區分樂觀偏頗或悲觀偏頗，實證結果顯示，在具有影響力股吧投資專家首次加入，相較於與其追蹤同一家公司之能力低的分析師，能力高分析師樂觀偏頗的幅度及悲觀偏頗的幅度均會顯著下降較多。實證結果亦顯示，當具有影響力股吧投資專家首次加入，追蹤同一家公司之能力佳分析師之盈餘預測錯誤會顯著減少。

In recent years, with the popularity of the Internet and the rise of online investment platforms in China, the investment opinions expressed by investment experts in Gub's forum have attracted attention from investors. Gub's statements create competitive pressure for analysts. If the investment experts on Gub's platform and analysts track the same company, the analysts may have incentives to improve the accuracy of their earnings forecasts for reputation. This study aims to examine whether forecast biases and forecast errors of analysts with different abilities will change after Gub's investment experts express their opinions on the same firm for the first time.
This study differentiates analysts' earnings forecast bias into optimistic or pessimistic bias. Empirical results show that compared to analysts with low ability, both the magnitude of optimistic bias and pessimistic bias for analysts with high ability decreases significantly when influential investment experts express their opinion for the first time. Empirical results also show that earnings forecast errors of analysts with higher ability are significantly reduced when influential investment experts express their views for the first time at the same firm that analysts follow.

一、中文部分
公言磊，2010，公司因素對財務分析師盈餘預測特性影響的實證研究，財經問題研究 第3期，第72-78頁。
石勇、唐靜與郭琨，2017，社交媒體投資者關注、投資者情緒對中國股票市場的影響，金融保險研究，第7期，第45-53頁。
伊志宏與江軒宇，2013，明星vs非明星：分析師評級調整與信息屬性，經濟理論與經濟管理，第10期，第93-108頁。
李勇、王莉與王滿倉，2015，明星分析師的推薦評級更具價值嗎？—基於媒體關注的視角，投資研究，第34卷第5期，第143-160頁。
李麗青，2012，《新財富》評選的最佳分析師可信嗎？—基於盈利預測準確度和預測修正市場反應的經驗證據，投資研究，第31卷第7期，第54-64頁。
肖萌，2015，《新財富》能夠帶來財富嗎?—聲譽視角下分析師評級的市場反應研究，會計與經濟研究，第29卷第5期，第49-56頁。
金秀、姜尚偉與苑瑩，2018，基於股吧信息的投資者情緒與極端收益的可預測性研究，管理評論，第30卷第7期，第16-25頁。
金雪軍、祝宇與楊曉蘭，2013，網絡媒體對股票市場的影響—以東方財富網股吧為例的實證研究，新聞與傳播研究，第12期，第36-51頁。
段江嬌、劉紅忠與曾劍平，2014，投資者情緒指數、分析師推薦指數與股指收益率的影響研究—基於我國東方財富網股吧論壇、新浪網分析師個股評級數據，金融市場研究，第11期，第60-64頁。
胡娜、鄭曉薇與周銘山，2014，聲譽如何影響證券分析師的預測行為?，管理科學，第36卷第6期，第87-93頁。
許祐嘉，2021，股吧投資專家對分析師股票推薦影響之探究，國立臺灣師範大學管理研究所碩士論文。
陳昱融，2021，股吧投資專家對分析師盈餘預測時間點影響之探究，國立臺灣師範大學管理研究所碩士論文。
黄宏斌、李然與毛天琴，2020，上市公司自媒體信息披露、市場行情與分析師盈余預測偏差，社會科學研究，第40卷第2期，第45-56頁。
彭琪淳，2021，股吧投資專家對分析師盈餘預測影響之探究，國立臺灣師範大學管理研究所碩士論文。
葉德磊、姚占雷與劉小舟，2017，公司新聞、投資者關注與股價運行—來自股吧的證據，人文與社會科學，第6期，第136-143頁。
熊熊、羅春春與張燁，2017，股吧和交易:股吧中的信息內容研究，系統科學與數學，第2359-2374頁。
盧建彰，2021，股吧投資專家對分析師追蹤影響之探究，國立臺灣師範大學管理研究所碩士論文。
二、英文部分
Bagnoli, M., S. G. Watts, and Y. Zhang. 2008. Reg-FD and the competitiveness of all-star analysts. Journal of Accounting and Public Policy 27: 295-316.
Banker, R. D., J.A. Khavis, and H.-U. Park. 2018. Crowdsourced earnings forecasts: Implications for analyst forecast timing and market efficiency? Working Paper.
Bantock, H., and R. Heaney. 2017. Are All-American analysts better: A study using 2010 IBES target prices? Working Paper.
Bradshaw, M. T., L. D. Brown, and K. Huang. 2013. Do sell-side analysts exhibit differential target price forecasting ability? Review of Accounting Studies 18: 931-955.
Beyer, Anne and I. Guttman. 2011. The effect of trading volume on analysts' forecast bias. The Accounting Review 86(2): 451-481.
Chen, H., P. D., Yu, J. Hu, and B.-H Hwang. 2013. Wisdom of crowds: The value of stock opinions transmitted through social media. The Review of Financial Studies 27(5): 1367-1403.
Chen, S., B. Lin, R. Lu, and H. Ma. 2021. Stock market openness and analyst forecast bias. Journal of Accounting and Public Policy 40(6): 1-20.
Clement, M. B., L. Koonce, and T. J. Lopez. 2007. The roles of task-specific forecasting experience and innate ability in understanding analyst forecasting performance. Journal of Accounting and Economics 44(3): 378-398.
Dang, C., S. Foerster, Z. F. Li, and Z. Tang. 2021. Analyst talent, information, and insider trading. Journal of Corporate Finance 67, Forthcoming.
Dugar, A., and S. Nathan. 1995. The effect of investment banking relationships on financial analysts' earnings forecasts and investment recommendations. Contemporary Accounting Research 12: 131-160.
Giannini, R., P. Irvine, and T. Shu. 2015. The convergence and divergence of investors' opinions around earnings news: Evidence from a social network. Journal of Financial Markets 42: 94-120.
Gu, Z., and J. S. Wu. 2003. Earnings skewness and analyst forecast bias. Journal of Accounting and Economics 35: 5-29.
Hong H., and J. D. Kubik. 2003. Analyzing the analysts: Career concerns and biased earnings forecasts. The Journal of Finance 58(1): 313-351.
Hong, Harrison and M. Kacperczyk. 2010. Competition and bias. The Quarterly Journal of Economics: 1683-1725.
Jacob, J., T. Z. Lys, and M. A. Neale. 1999. Expertise in forecasting performance of security analysts. Journal of Accounting and Economics 28: 52-82.
Jame, R., R. Johnston, S. Markov, and M. Wolfe. 2016. The value of crowdsourced earnings forecasts. Journal of Accounting Research 54(4): 1077-1110.
Jame, R., S. Markov, and M. Wolfe. 2021. Can FinTech competition improve sell-side research quality? The Accounting Review, Forthcoming.
Kim, Y., G. J. Lobo, and M. Song. 2011. Analyst characteristics, timing of forecast revisions, and analyst forecasting ability. Journal of Banking and Finance 35(8): 2158-2168.
Lang, M. H., and R. J. Lundholm. 1996. Corporate disclosure policy and analyst behavior. The Accounting Review 71(4): 467-492.
Lement, M. B.1999. Analyst forecast accuracy: Do ability, resources, and portfolio complexity matter? Journal of Accounting and Economics 27(3): 285-303.
Lin, H.-W., and M. F. McNichols. 1998. Underwriting relationships, analysts' earnings forecasts and investment recommendations. Journal of Accounting and Economics 25: 101-127.
Lim, Terence. 2001. Rationality and analysts' forecast bias. The Journal of Finance 1(1): 369-385.
Michaely, R., and K. L. Womack. 1999. Conflict of interest and the credibility of underwriter analyst recommendations. The Review of Financial Studies 12: 653-686.
Schafhautle, S., and D. Veenman. 2021. Crowdsourced earnings expectations and the salience of sell-side forecast bias. Working Paper.
Stickel, S. E. 1992. Reputation and performance among security analysts. The Journal of Finance 47(5): 1811-1836.
Wang, Z., L. Sun, and K. C. J. Wei. 2020. Does competition induce analyst effort? Evidence from a natural experiment of broker mergers. Journal of Banking and Finance, Forthcoming.
Walther, B. R. and R. H. Willis. 2013. Do investor expectations affect sell-side analysts' forecast bias and forecast accuracy? Review Account Student 18: 207-227.