For those who, like myself, are inclined to be eclectic, no comprehensive commitment to one approach rather than another needs to be made. What is involved, rather, is the selection of the approach best suited to deal with the problems at hand.
Because internal organization experiences added bureaucratic costs, the firm is usefully thought as the organization of last resort: try markets, try hybrids (long term contractual relations into which security features have been crafted), and resort to firms when all else fails