Headshot of John McCoy


John McCoy

I am a Ph.D. student in the Brain and Cognitive Sciences Department at MIT, where I am co-advised by Drazen Prelec and Josh Tenenbaum. Amongst other awards, I am a South African recipient of the International Fulbright Science and Technology Award.

I am interested in the processes underlying human judgment and decision making, and applying our knowledge of such processes to issues in marketing and public policy. I use a combination of behavioral experiments and formal modeling, drawing on ideas from psychology, economics, marketing, Bayesian statistics, and computer science.

Much of my current research focuses on the problem of aggregating judgments from many people, including in situations where the majority may be wrong and the truth may be unverifiable. I work on computational models for solving this problem, and psychological questions inspired by these models.

Crowds, and their wisdom

Our new solution to extracting wisdom from the crowd says that one should select not the "most popular" answer, but rather the "surprisingly popular" answer. That is, select the answer which is more popular than the crowd itself predicts. We justify this theoretically, and show that it delivers superior performance across a range of domains.

Prelec, D., Seung, H.S., and McCoy, J. “A solution to the single-question crowd wisdom problem” Nature, 2017, 541, 532-535.

Nature crowd wisdom cover

Representative press:

Wall Street Journal, Bloomberg, Quartz,
MIT news, Scientific American, NPR

In a new working paper, we draw on these ideas to develop a statistical model for belief aggregation that operates both on separate and multiple questions, and additionally infers respondent expertise:

McCoy, J. and Prelec, D. "A statistical model for aggregating judgments by incorporating peer predictions" , MIT Working paper

A non-complete selection of ongoing projects in this space, with numerous collaborators, includes:

Individuals, and their quirks

Ongoing projects on how people make judgments and decisions include:

Graph theory

I have written some mathematics papers:

Henning, M.A., McCoy, J. and Southey, J. "Graphs with maximum size and given paired-domination number" Discrete Applied Mathematics, 2014, 170: 72-82.

Henning, M.A., and McCoy, J. "Which trees have a differentiating-paired dominating set?" Journal of combinatorial optimization, 2011, 22.1: 1-18.

Henning, M.A., and McCoy, J. "Total domination in planar graphs of diameter two" Discrete Mathematics, 2009, 309.21: 6181-6189.

McCoy, J., and Henning, M.A. "Locating and paired-dominating sets in graphs" Discrete Applied Mathematics, 2009, 157.15: 3268-3280.

Dorbec, P., Henning, M. A., & McCoy, J. "Upper total domination versus upper paired-domination" Quaestiones Mathematicae, 2007, 30(1), 1-12.

Apparel for discerning babbies

"Always be closing..."