The combination of cheap jets with greater fuel efficiency and a critical mass of these critters in the sky can, in theory, lower the price per seat considerably.

FORBES: Private Jet Boom

In theory, such specialisation should increase the efficiency of the venture-capital process, as it does in other industries.

ECONOMIST: Money to burn

In theory, the PPP was meant to harness the efficiency of the private sector and, in return for healthy profits, transfer risks to the firms doing the work.

ECONOMIST: The Tube upgrade deals: Finis | The