The newspaper "lost" twenty wallets around the city at the start of this month repeating the famous honesty test of world cities set up by Readers' Digest magazine in 1996.
But whereas in 1996, all ten of the wallets left in Oslo were returned untouched, this time five out of twenty were kept by their finders, while three of those returned had had some or all of the cash removed.
The wallets the newspaper left contained a DNB bank card, 300 kroner in cash, commuter cards, and the business card of an Aftenposten journalist.
The 1996 experiment ranked Oslo the world's most honest city, well ahead of Stockholm, where only seven wallets came back.
Alexander Cappelen, a professor at the Norwegian School of Economics, cited a French study which argues that high levels of trust underpin the high standard of living in Scandinavian countries.
"Trust is a more important resource for Norway than oil," he said . "So this is something politicians should take seriously."