Ad hoc associations of people and capital

From the Hollywood article (thanks, BenK), an observation regarding changing business structures:
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The days of the tightly integrated corporation are largely behind us. Rather than the corporate juggernauts of the 19th and 20th centuries, 21st-century enterprises more closely resemble ad hoc associations of people and capital working on ever-shorter timelines toward ever-more-specific goals. Of the corporations on the Fortune 500 in 1955, fewer than 70 remain today. In the 1960s, the average lifespan of a Fortune 500 company was 75 years, whereas today it is only 15 years, and that number is declining. ... [T]he idea of the corporation — of the business enterprise as a concrete and permanent thing — is increasingly inadequate to communicate the reality of how business works.