When one thinks of the rich in the United States, the first people who come to mind are the megabillionaires whose extravagant consumption, eye-popping wealth, and notorious political interventions have transformed them into household names. Perched atop the Forbes 400 list of America’s richest individuals are Silicon Valley moguls and Wall Street executives who command some of the most prominent corporations in America.

Beneath this elite stratum of capitalists lies a vastly less conspicuous group of still-wealthy but lesser-known business owners. Far more numerous and more geographically dispersed across the country than their billionaire brethren, this “American Gentry” exercises great influence on local, state, and even national politics. The relatively scant attention they receive compared to their headline-grabbing compatriots means that their collective effect on the American wealth distribution has been hitherto mostly unexamined.

A new book by Princeton economist Owen Zidar and University of Chicago economist Eric Zwick attempts to correct this relative neglect by quantifying the place of “The Everywhere Millionaire” in the American wealth distribution. The book is a popular exposition of previous academic work that celebrated scholars of inequality Emmanuel Saez and Gabriel Zucman deemed (despite some critiques) an “important contribution” to the estimation of wealth inequality in the United States.