Via Paul Krugman:
McKinsey released the alleged results of a study showing that large numbers of firms will drop health insurance coverage once the Affordable Care Act goes fully into effect. This is very different from the results of other studies, notably the Congressional Budget Office assessment of the act.
So when the McKinsey alleged study made headlines, the firm was pressed to explain how the study was conducted. And it has refused to answer.
It’s hard to escape the conclusion that the study was embarrassingly bad — maybe it was a skewed sample, maybe the questions were leading, maybe there was no real data at all. Whatever.
The important thing is that this must not stand. You can’t enter the political debate with strong claims about what the evidence says, then refuse to produce that evidence.
And it’s especially bad when the media give your claims lots of attention, while barely covering the furor over the refusal to explain where those claims come from.
People should start taking notes. A claim has to be supported with evidence and a good methodology that interprets the evidence correctly. In addition, McKinsey has shown that private firms, like Standard & Poor’s and Moody’s, are bias in nature because their interests are more aligned to the people they are serving.