Most of this book was written in late 2005, through the summer of 2006. I mention this because these months have been among the most fruitful periods of new research on Wal-Mart, and new studies emerge with remarkable frequency. A number of the papers I cite in this book are unpublished and forthcoming papers, a fact which reflects the freshness of the questions at hand. Still, the review of existing studies and new empirical analysis in this book is much broader in scope than is elsewhere available.
One feature of this book that bears comment is the ease with which academics researchers including myself, criticize existing studies. This will be unfamiliar to many readers. I want to be clear that this criticism is largely the mechanism we use to guide further exploration, not censure one another. Or as Isaac Newton asks in the preface to Principia “… the defects I have been guilty of … be not so much reprehended as kindly supplied, and investigated by new endeavors of my readers.” To give weight to this point, you will find I share criticism others have of my research (even agreeing in some instances).
Recently, a number of conscientious researchers of Wal-Mart have been criticized for having their research directly, or indirectly sponsored by Wal-Mart or their foes. This includes several researchers I specifically thank in the acknowledgments (whose work both criticizes and lauds Wal-Mart). I am personally skeptical that these economists would trade off their reputations for these payments; it just doesn’t pay off, and being economists they are all highly rational. More to the point, I cannot find any sign of bias in their work, even when I disagree with their findings. (That is not true of course, of many recent popular books on the matter, and I often call their objectivity into question). Yet, it is still useful to make a full disclosure: I have no pecuniary link to Wal-Mart other than as a consumer (I once calculated diaper expenses topped $1,500 per year!). I am affiliated with two public universities and a well-known think tank. It is almost certain that researchers at both institutions have done work sponsored by both Wal-Mart and its foes. I don’t know what they might be, and have no financial connection to them. In short, any bias I demonstrate in this book is due to far baser motivations than my simple mercenary inclinations.