A Chicago-based consulting firm, HVS Convention, Sports & Entertainment Facilities Consulting, released a study saying that despite claims by the Chargers, the stadium would only generate about $2.3 million extra in additional hotel tax revenue each year, but estimated the annual public costs would be $67 million for the operation and constructions of the project. They also stated that attempts in other cities to combine a convention center with a football stadium had largely failed, citing Indianapolis, St. Louis and Atlanta.