Noise is the absence of a signal. A biased signal is fine, just account for the bias.
ADP is huge and covers a broad range of sectors. It would be a very interesting result (and a very extraordinary claim) if the employment data from non-ADP companies went in the opposite direction of ADP. I certainly see no evidence that firms underrepresented in ADP's data are hiring prodigiously.
ADP is huge and covers a broad range of sectors. It would be a very interesting result (and a very extraordinary claim) if the employment data from non-ADP companies went in the opposite direction of ADP. I certainly see no evidence that firms underrepresented in ADP's data are hiring prodigiously.