You might cite the literature on the late 19th century economy which demonstrates that the rise of big business led to more output, greater efficiency, lower prices, and rising real wages. And that collusion and corruption came from state involvement, starting with the railroads subsidies and culminating in anti-trust legislation.
Burton Folsom, The Myth of the Robber Barons.
Thomas DiLorenzo, How Capitalism Built America.
Gabriel Kolko, The Triumph of Conservatism.
Murray Rothbard, The Origin of the Federal Reserve.