From New Scientist:

"In effect, less than 1 per cent of the companies were able to control 40 percent of the entire network," says Glattfelder, researcher at the ETH. Most were financial institutions. The top 20 included Barclays Bank, JPMorgan Chase & Co., and The Goldman Sachs Group.

John Driffill of the University of London, a macroeconomics expert, says the value of the analysis is not just to see if a small number of people controls the global economy, but rather its insights into economic stability.

Concentration of power is not good or bad in itself, says the Zurich team, but the core's tight interconnections could be. As the world learned in 2008, such networks are unstable. "If one [company] suffers distress," says Glattfelder, "this propagates."

"It's disconcerting to see how connected things really are," agrees George Sugihara of the Scripps Institution of Oceanography in La Jolla, Calif., a complex systems expert who has advised Deutsche Bank.