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On the Reliability of I/B/E/S Earnings Announcement Dates and Forecasts


  • Daniella Acker
  • Nigel W. Duck



We add to the concerns raised in Ljungqvist, Malloy and Marston, 2009, Rewriting History, Journal of Finance, 64, 1935-1960, about the reliability of the I/B/E/S data provided by Thomson Reuters (TR). Many of the dates reported as earnings announcement dates are not earnings announcement dates; there are inconsistencies between these dates and those reported in Worldscope, another TR database; and summaries of financial analysts’ forecasts can be misleading. Following discussions with the authors, TR has reviewed approximately 2 million records and is in the process of correcting some 50,000 of them. Further reviews are under way.

Suggested Citation

  • Daniella Acker & Nigel W. Duck, 2009. "On the Reliability of I/B/E/S Earnings Announcement Dates and Forecasts," Bristol Economics Discussion Papers 09/611, Department of Economics, University of Bristol, UK.
  • Handle: RePEc:bri:uobdis:09/611

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    I/B/E/S; Worldscope; earnings announcements; analysts’ forecasts;

    JEL classification:

    • G00 - Financial Economics - - General - - - General
    • G10 - Financial Economics - - General Financial Markets - - - General (includes Measurement and Data)
    • G14 - Financial Economics - - General Financial Markets - - - Information and Market Efficiency; Event Studies; Insider Trading
    • G32 - Financial Economics - - Corporate Finance and Governance - - - Financing Policy; Financial Risk and Risk Management; Capital and Ownership Structure; Value of Firms; Goodwill

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