On the importance of time in IT-related event studies

Until now, time has been mainly used as a variable in IT-related event studies to explain the delayed impact of IT investments on firm value and productivity. Yet, the timing of the event announcement itself, due to investor sentiment, may have an effect on its valuation by the capital market. Using the example of product source code releases as open source, I find that market valuation takes a curvilinear shape over time due to investor sentiment caused by the rise and fall of the dot.com bubble. Future IT-related event studies will need to take this potentially interfering effect into account.