Free-market anarchism may refer to diverse economic and political concepts like those proposed by individualist anarchists and libertarian socialists such as the Europeans Émile Armand, Thomas Hodgskin, Miguel Giménez Igualada and Pierre-Joseph Proudhon, or the Americans Stephen Pearl Andrews, William Batchelder Greene, Lysander Spooner, Benjamin Tucker and Josiah Warren, among others; and occasionally anarcho-capitalists such as David D. Friedman or various anti-capitalists, left-libertarians and left-wing market anarchists such as Carson, Chartier, Charles W. Johnson, Konkin, Roderick T. Long, Sheldon Richman, Chris Matthew Sciabarra and Brad Spangler.