As academic researchers become experts in one or more fields, they have often specialized in writing about subjects within their expertise, often earning prestige as sources of reliable information and perspectives on these topics.
One source of expert authors on various subject matters is the Scholars Strategy Network. Here's how they determine experts, as described by their About page:
"The Scholars Strategy Network (SSN) is a national membership organization made up of college- and university-based researchers interested in improving policy and strengthening democracy. Founded in 2011 by Theda Skocpol, Victor S. Thomas Professor of Government and Sociology at Harvard University, SSN has grown into a network of over 1800 researchers in 47 states. SSN members organize themselves into local chapters across the United States, working to advance the use of research wherever policy decisions are made - from city halls to state legislatures to Washington."
Professor Emeritus of International Affairs, University of Pittsburgh-Pittsburgh Campus
Professor of History, University of South Florida-Tampa
Associate Professor in the School of Information Sciences at the University of Illinois at Urbana Champaign
Professor and Chair of Sociology, Furman University
Professor of Criminology, Law & Society, University of California-Irvine
Associate Professor of Sociology, University of Michigan-Ann Arbor
Postdoctoral Research Associate, Humanities Research Center, Rice University