Part I describes the proper methodology for assessing Miranda's costs; it maintains that Miranda's effects should be measured, not by looking at suppression motions filed after police have obtained a confession, but rather by examining how many confessions police never obtain because of Miranda. Part II reviews the available empirical evidence concerning Miranda's effect on confession rates and on the role of confessions in obtaining convictions. Overall, these studies suggest that Miranda has resulted in a lost confession in approximately one out of every six criminal cases and that confessions are needed to convict in one out of every four cases. Part III quantifies Miranda's costs, in terms of both lost cases and more favorable plea bargains for defendants. Part IV responds to some anticipated objections that might be raised to the extrapolations that the author's calculus involves. Part V examines whether this concept of a cost to Miranda is a "legitimate" one. Part VI assesses Miranda in the context of these costs and concludes that they are unacceptably high, particularly because alternatives such as videotaping police interrogations can more effectively prevent coercion while reducing Miranda's harms to society. 3 tables and 645 footnotes