This includes a list of sites that are the best place to start searching for data.
Publications by Consulting Firms
This includes a list of links to the publicly available publication websites of the popular consulting firms.
The complete articles are available only to the students of IIM Ahmedabad through the report repository.
McKinsey & Company: http://www.mckinsey.com/insights
Bain & Company: http://www.bain.com/publications/index.aspx
Strategy& [Previously Booz & Co]: http://www.strategy-business.com/
AT Kearney: http://www.atkearney.com/ideas-insights