Mũthoni's primary research interest is in development economics looking at how social networks affect individuals’ behaviour in developing countries. Muthoni has worked in Kenya, Malawi, and Zambia. She has an A.B. in Applied Mathematics and Economics from Harvard University and a Ph.D. in Economics from Yale University. Mũthoni is the recipient of grants from J-PAL, PEDL, Kilimo Trust, and The Russell Sage Foundation among others.
