An article in Fortune magazine about expensive museum acquisitions includes this bit about the impact of a work’s copyright status on demand for viewing the original (emphasis added):

An example of the long-term benefit of an iconic artwork such as “Adele” can be found at the Art Institute of Chicago, home to three of the most famous paintings in America: Georges Seurat’s composition of colorful dots, “Sunday Afternoon on the Island of La Grande Jatte” (acquired in 1926); Grant Wood’s portrait of farmer, wife, and pitchfork titled “American Gothic” (in 1930); and Edward Hopper’s fluorescent-lit diner, “Nighthawks” (in 1942).

Generations of Chicagoans have grown up with the three paintings and consider Chicago’s stewardship of them a point of civic pride. And because each image is in the public domain – anyone from an ad firm to a television producer to a T-shirt designer can use the images without paying for them or needing contractual permission – the paintings automatically market themselves, the museum, and Chicago.

Perhaps a forward-looking museum should encourage artists to CC license works about to be acquired.