Daniel Grant examines the question in the Wall Street Journal. On the one hand, those concerned with keeping artworks in the public trust should favor private sales to other museums. But the hysteria that surrounds deaccessioning tends to push people to auction:
"In most cases, museums prefer going to auction. Whatever criticism these institutions receive for selling objects only increases if they don't do it that way. Take, for example, the Albright-Knox Art Gallery in Buffalo, N.Y., a museum devoted to contemporary art that sold 207 of its older artworks at Sotheby's, raising $67.2 million. There was some discussion at the board level of selling pieces directly to other museums or through art dealers, said Louis Grachos, the Albright-Knox's director, 'but in the end, it just seemed like going the auction route was the safest and wisest choice.' Certainly wise in this case, but why safest? 'We were under a microscope, and people were looking for any reason whatsoever to attack us,' he said. 'Going to public auction made all our actions transparent. No one could claim that we were pursuing back-room deals.'"
But Grant suggests that "museum directors fearful of public criticism might want to broaden their outlook. The Albright-Knox was probably right to take its disparate objects to auction, ... while artworks that ought to stay together ... call for a perhaps less lucrative 'friendly' sale to another institution. It made sense that when Philadelphia-based Thomas Jefferson University sought to raise money by selling its painting 'The Gross Clinic' by Thomas Eakins, it gave first dibs to the Philadelphia Museum of Art .... The subject of the painting, Dr. Samuel Gross, was a renowned Philadelphia physician, and Eakins himself spent most of his life in that city. Raising money and doing well by the art aren't mutually exclusive goals."