He returns the others to his colleague to show that he has taken only the correct number, and the surplus envelopes are destroyed without being opened.

ECONOMIST: Cryptography

In other words, haggling not only determines how the surplus from trade is divided, it also reduces the surplus once the cost of the haggling is taken into account.

FORBES: Haggling, Social Norms, and Economic Efficiency

Given actual exchange-rate movements, the IMF reckons that if the only thing surplus countries had done was to let their currencies rise, then growth might have ended up declining by between two and four percentage points.

ECONOMIST: Economics focus