Both the US government and BP have refused to explain the math behind their spill calculation; and methods for a more accurate estimate of the flow rate have not been applied, according to the NY TImes. Experts suggest the actual rate may be 5 times as great as the stated rate, 5,000 barrels per day.
UPDATE: The May 16 NY Times added the following:
Scientists studying video of the gushing oil well have tentatively calculated that it could be flowing at a rate of 25,000 to 80,000 barrels of oil a day. The latter figure would be 3.4 million gallons a day. But the government, working from satellite images of the ocean surface, has calculated a flow rate of only 5,000 barrels a day.
BP has resisted entreaties from scientists that they be allowed to use sophisticated instruments at the ocean floor that would give a far more accurate picture of how much oil is really gushing from the well.
“The answer is no to that,” a BP spokesman, Tom Mueller, said on Saturday. “We’re not going to take any extra efforts now to calculate flow there at this point. It’s not relevant to the response effort, and it might even detract from the response effort…”