Bank Transfer Day Black Box

The Credit Union National Association (CUNA) claims that more than 40,000 consumers joined credit unions on November 5, “Bank Transfer Day.”

CUNA extrapolated the results to the entire industry based upon the results from a survey sent to 1,100 credit unions.

However, CUNA conveniently failed to disclose the participation or response rate to this survey.

Why all the mystery?

Is it due to a low response rate?

A high response rate helps to ensure that survey results are representative of the credit union industry. Without a good response rate, the survey is unlikely to produce accurate and useful results.

Furthermore, the results of the survey may be suspect because of a self-selction bias associated with the credit unions that responded to the survey. A self-selection bias is possible whenever the group being surveyed has any form of control over whether to participate in the survey. Therefore, it is possible that the the credit unions that responded to the survey are disproportionately represented by credit unions that added members on Bank Transfer Day, not those that did not add members.

The failure to disclose the response rate and the potential of self-selection bias raises doubts about the accuaracy and usefulness of the survey's results.