What is the value of the research we do? The typical way we have to evaluate the impact of research is to count citations, and possibly weigh them in some way, in Economics and any other sciences (except maybe where patents are relevant). But this only evaluates how the research output is viewed within a narrowly defined scientific community. The contribution to social welfare is an entirely different beast to evaluate.
Robert Hofmeister tries to give research some value. The approach is to consider the scientific process through cohorts, where each wave provides fundamental research as well as end-applications based on previous fundamental research. A particular research results thus can have a return over many generations. It is an interesting way to properly attribute the intellectual source of a new product or process, but the exercise is of little value if it is not possible to quantify the social value of the end-application. Indeed, Hofmeister goes back to using citations in Economics for a data application, which is equivalent to evaluate research only within the scientific community. In terms of the stated goal of the paper, we are back to square one. In terms of getting a better measure of citation impact, this is an interesting application of an old idea. And the resulting rankings of journals and articles look very much like those that are already available.