Product counterfeiting is growing internationally in scope, scale, and threat. The economic impact is believed to be in hundreds of billions of dollars. There is growing awareness of the developed and developing countries' public health vulnerabilities from a range of counterfeit products such as pharmaceuticals, food additives, consumer products, automobile replacement parts, and consumer electronics. Since human actors are perpetrating the infringement, product counterfeiting research and prevention is rooted in the behavioral sciences and criminology. This study reviewed the previous research efforts to quantify the global economic impact of counterfeit trade, as well as to identify the scholarly works that made use of these estimates, with the intent of examining the underlying methodologies. While theorists and practitioners have been very diligent and intense in their efforts, there is a lack of a scholarly quantitative methodology needed to support corporate investment in countermeasures and to help governments prioritize resources toward regulations and laws. This study found that quantitative estimates were based on three core reference documents. Addressing this is an applied criminology challenge. Abstract published by arrangement with Taylor and Francis.