What are the differences in the economic efficiency regarding de-jure
standards and de-facto/consortia-standards?

(de-jure = standards of recognized standardisation bodies e.g. ISO, ANSI)
(de-facto/consortia = standards of the W3C, ATM-forum or Microsoft
Windows etc.)

Questions I'd ask myself when thinking about the main question:
From which type of standard does the user benefit the most?
Which type of standard is the most efficient for companies and why?
Thinking about further devellopment of a standard, the different
standardization processes influence the economic efficiency, but how?

Good topic for a book.