He conducts research on information economics, covering such topics as communications markets, the economics of networks, intellectual property, social effects of technology, and productivity effects of information. As co-developer of the concept of “two-sided networks,” Marshall has been a major contributor to the theory of network effects, a set of ideas now taught worldwide. His co-authored article on the subject is a Harvard Business Review top 50 of all time.
Awards include two patents, National Science Foundation IOC, SGER, SBIR, iCorp and Career Awards, and eight best paper awards. His articles and commentary have appeared in Science, Nature, Management Science, Harvard Business Review, The New York Times, and The Wall Street Journal.