In Robinson v. Commissioner, the Tax Court held that an individual cannot deduct interest paid on tax deficiencies when the deficiencies arose in the conduct of the business of a sole proprietorship. While the Robinson holding itself is not surprising in light of six courts of appeals decisions that arrived at the same result, the fact that the Robinson court relied heavily on congressional staffers’ statements printed in the Blue Book ignited immediate controversy: only six judges signed the plurality opinion in Robinson, and eight other judges, whether concurring or dissenting, articulated strong concern that the plurality opinion accorded too much interpretative weight to non-authoritative explanations in the Blue Book. Furthermore, following the issuance of the Robinson opinion, several leading tax practitioners voiced concerns that the Robinson plurality had further confused basic principles of statutory construction by overvaluing statements from the Blue Book; they further predicted that this confusion would have widespread repercussions throughout the field of tax law and beyond. In little more than a year, these predictions began to be fulfilled as the first court to attempt to rely on the Blue Book in a Robinson fashion notably struggled to understand the extent of the Blue Book’s authority as a tool for statutory construction.This Note assesses the significance of the Robinson court’s debate regarding the role that the Blue Book should play as an instrument of statutory construction. Part I of this Note introduces the facts of the case, describes the pertinent statutory framework, and outlines the parties’ arguments. Part II summarizes the differing ways in which the Robinson plurality, concurring, and dissenting opinions interpreted the value of the Blue Book as a tool of statutory construction. Part III outlines the new doctrinal complexity that practitioners face when attempting to apply the Blue Book post- Robinson. This is accomplished by describing 12 of the most important factors that practitioners should now consider when using the Blue Book for statutory construction purposes. And Part IV concludes.