Every major American art museum is sitting on assets that, from the outside, look enviable. They’re called works of art. If they’re by Vincent van Gogh or Frida Kahlo or Jackson Pollock, they may be worth tens, or even hundreds, of millions of dollars.

Even if they’re by less famous artists and consigned to storage — along with perhaps 90 percent of any given museum’s collection — they can still be valued at eye-watering amounts. Set beside, say, a scary budget deficit or the prospect of having to lay off employees, this knowledge can take on an almost voluptuous glow.

To counter the constant temptation to regard art works as a way to get quick cash, the museum world heavily polices the sale of works from permanent collections — otherwise known as deaccessioning. The powerful Association of Art Museum Directors, made up of directors of museums in the United States, Mexico and Canada, has long frowned on any museum that sells off art for purposes other than acquiring new art.

AAMD’s frowns have an effect. Museums that dare to ignore its guidelines — as the Berkshire Museum in Pittsfield, Mass., did in 2018, ultimately selling more than 20 works from its collection to raise money for a renovation — are censured, sanctioned and publicly shamed. For a renegade — or perhaps simply desperate — museum director, a decision to sell works from the collection, even if it’s to raise money deemed necessary for survival, might mean career death.

However, in an unprecedented move, and as a direct result of the coronavirus pandemic, the AAMD has recently relaxed its guidelines. It’s too soon to gauge the effect, but it is already big news in the art world. Once unthinkable, the notion of selling off a Claude Monet or two to plug a budgetary hole — or to fend off a total financial meltdown — is suddenly something to contemplate.