The Problem of Line-Drawing

In Quantitative Model for Measuring Line-Drawing Inequity, Bradley Borden tackles the extremely difficult problem of line-drawing: when two people or situations are similar, how can we justify treating them differently? Borden’s Article focuses on the inequity that he claims arises from subjecting some gains from real-estate sales to the higher ordinary income tax rate while taxing other real-estate gains as capital gains, subject to a lower rate. Borden presents a model that he suggests can be applied in many areas. Borden’s model—I will call it the “Inequity Model”—is not meant to predict outcomes or provide a causal explanation. Rather, this is the sort of model that, as I have described elsewhere, will be helpful to the extent it focuses or develops our intuitions or highlights previously overlooked questions or assumptions.\nIn this brief response, I first describe the kind of fairness that the Inequity Model presents (not necessarily, as it turns out, line-drawing fairness), and then I explain why the Inequity Model as implemented in Borden’s Article does relate to line-drawing fairness. I raise some concerns about the Inequity Model as presented, and I highlight one of its larger problems by attempting to apply it to another area of law—speed limits. I conclude that while Borden’s Article takes a quantitative and possibly helpful approach to an important question, the Inequity Model falls short of the Article’s stated goals.