A TIARA adorned with pearls worn by French Empress Eugenie, which was among the items stolen by thieves during a heist at Paris鈥 Louvre Museum on Oct. 19, on display in this undated still frame from a video. 鈥 LOUVRE MUSEUM/HANDOUT VIA REUTERS

By Robert Cyran

NEARLY A WEEK after they stole perhaps $100 million of royal jewelry from Paris鈥 Louvre museum, the thieves are still at large. What鈥檚 unusual about their spectacular heist isn鈥檛 just the prestigious location, the in-broad-daylight execution, or the incredible monetary value. It鈥檚 that the perpetrators took something they could sell for a change.

After using a crane to climb through a second-floor window before cutting into displays and threatening staff, the criminals managed to escape by scooter within eight minutes. The temptation is to assume operations like this are sophisticated, in the mold of silver-screen capers like Ocean鈥檚 Twelve, The Thomas Crown Affair, or How to Steal a Million. After all, media, police, and hapless museums have an incentive to play along in order to attract public attention, deflect blame if they fail to crack the case, and earn praise if they succeed.

While thieves鈥 taste may be exquisite, the methods aren鈥檛. Researchers find that most use brute force and physical intimidation of guards for access. While half used deception, including inspired examples 鈥 a Brazilian robbery during carnival and Norwegian heists during an Olympic ceremony 鈥 burglars mostly just wore balaclavas.

The choice of location isn鈥檛 unusual either. France is the most common site for museum theft in the world, with Italy second, according to Interpol and the Federal Bureau of Investigation data. These countries are ground zero for the world鈥檚 best-known art.

Oddly, jewelry isn鈥檛 a popular choice of target. Nearly six times as many paintings are nabbed as gold or gems.

This represents a colossal market failure. Well-known paintings are nearly impossible to sell. Few buyers will touch one with an obviously illegal provenance, and The Art Loss Register鈥檚 extensive database provides an easy means of checking. All this for little payoff: black-market prices are less than 10% of open-market value, according to the Federal Bureau of Investigation鈥檚 Art Theft Program.

These difficulties mean that stolen paintings often linger in limbo, before sometimes resurfacing. Two Laughing Boys with a Mug of Beer, by Dutch painter Frans Hals, has been nicked three times in four decades.

Gold and many gems, on the other hand, are easy to sell, hard to trace, and fetch good prices. Society may also be better off if museum thieves stuck to jewelry. A horrible outcome, say thieves tearing apart a necklace, leaves hope for reconstruction. A painting burned or thrown in the river is gone forever. 鈥 Reuters Breakingviews