I am looking for papers which argue that IT investment results in
higher profitability for corporations, based on quantitative analyses.

I know that recent pepers such as "IT doesn't matter" and "Intangible
Asset" point out that IT has become a commodity and therefore
investing in IT no longer give businesses competitive advantage.  But
I think that there once was a time when IT investment directly
resulted in increased profitability, so papers that quantitatively
discuss the business benefits of IT investment should exist.

- The more academic the better.  The papers must be objective, and
should have peer reviews.  Studies by universities and research
institutions are good, but newspaper/magazine articles are not
helpful.
- Research on major corporations in the US such as GE, Dupont,
Wal-mart, and Dell, are preferred over small or unpopular companies.
- IF you find tons of such research, let me know the ones that
illustrate that those invested more smartly are the ones that achieved
higher ROI.