Social interventionism is an action which involves the deliberate intervention of a public or private organization into social affairs for the purpose of changing them. In other words, it is a deliberate attempt to change society in some way, "an alteration of the social structure".
In the late 20th century, with the rise of the Washington Consensus, social interventionism fell out of favor in international political thought.
Socialism is an economic and political philosophy encompassing diverse economic and social systems characterised by social ownership of the means of production, as opposed to private ownership. It describes the economic, political, and social theories and movements associated with the implementation of such systems. Social ownership can take various forms, including public, community, collective, cooperative, or employee. As one of the main ideologies on the political spectrum, socialism is the standard left-wing ideology in most countries. Types of socialism vary based on the role of markets and planning in resource allocation, and the structure of management in organizations.
Socialist systems are divided into non-market and market forms. A non-market socialist system seeks to eliminate the perceived inefficiencies, irrationalities, unpredictability, and crises that socialists traditionally associate with capital accumulation and the profit system. Market socialism retains the use of monetary prices, factor markets and sometimes the profit motive. As a political force, socialist parties and ideas exercise varying degrees of power and influence, heading national governments in several countries. Socialist politics have been internationalist and nationalist; organised through political parties and opposed to party politics; at times overlapping with trade unions and other times independent and critical of them, and present in industrialised and developing nations. Social democracy originated within the socialist movement, supporting economic and social interventions to promote social justice. While retaining socialism as a long-term goal, in the post-war period social democracy embraced a mixed economy based on Keynesianism within a predominantly developed capitalist market economy and liberal democratic polity that expands state intervention to include income redistribution, regulation, and a welfare state.