Abstract: Disclosed herein are systems and methods that automatically identify instances where a site of a business merchant being analyzed for a test event is involved in another test event affecting a similar category of item that is being analyzed during a same time frame. The algorithm executed to automatically identify concurring events occurring at the same site calculates each event's date range, marks events as overlapping based on date range and primary category of items affected, and then determines concurring items in concurring events. The concurring events identified are accounted for in forecasting a lift over a baseline forecast in response to a promotion to estimate the effects of each promotion independently.