Residual concept of social welfare sees state assistance as temporary, minimal, requiring evidence of need, and available only after all other avenues of help have been exhausted. The cause of need can play a role in defining a person in need. This concept played a major role in shaping Canadian social work programs up to the late 1940's. The idea was that social welfare organizations should play a residual role to those of the private market and the family.

The institutional concept of welfare see social welfare programs as protecting individuals in society from the social costs of operating an industrialized capitalist market, rather than letting those costs fall on those who experience the risks of industrial society. Need is established based on the fact of need, without consideration of the cause of need. The shift to this view occurred in the post-war era.