From ECONOMIST.COM

When Jeffrey E. Horvitz was doing postgraduate work in psychology at the University of California at Los Angeles, he started to sell inexpensive prints on the side. He never got his doctorate but he caught the bug that turns an interest into an addiction.

Mr Horvitz's family real-estate business took him to Florida, where he became a wholesale dealer with a particular interest in 20th-century art. He also started collecting, and was fondest of his Braque still-life and a Franz Kline.

In the late 1980s the family business was sold, giving Mr Horvitz the time and money to collect more seriously. His chosen subject presented itself almost at random. "I love drawings," he says, "so I fell into Old Masters, which were relatively plentiful at the time, and not very expensive." He thought he would collect between six and a dozen drawings a year. "That was 25 years ago, and by 2007 I had 1,500 drawings instead of around 250. I was seriously off-plan."

He concentrated on French and Italian drawings. His collection of each was the finest of its kind in private hands, but when he found that the French outnumbered the Italian ten to one, he decided to thin out the latter. He found it hard going. "Selective personal deaccessioning is distressing and inconclusive," he discovered. "Because I could not decide on part, all of it had to go."

Sotheby's sold the Italian collection in January 2008. Included in the sale were dramatic pieces such as Lelio Orsi's "Apollo Driving the Chariot of the Sun" ("I like drawings with power and energy," says Mr Horvitz"). The sale fetched $9.2m, near double the estimate.

Mr Horvitz's collection of French drawing is encyclopaedic--Fragonard, Claude, Boucher and David are all brilliantly represented, and he says he bought them "for not much money". But he has begun to diversify into French painting and sculpture, specialising in artists who are out of fashion. Taste runs in very long cycles, he says, and he prefers lesser-known painters of the 15th to the 19th centuries, such as Jacques Bellange, Nicolas de Largilliere, Claude-Louis Desrais and Charles le Brun.

Specialising in French art has changed the character of the collection. Mr Horvitz keeps it in his house, near Boston, and around 150 pieces usually hang on the walls, but it is becoming steadily more institutionalised. There is a study room in the house and the collection is professionally managed.

There is also a specialist curator at Harvard's Fogg Museum, and Mr Horvitz gets one-third of his time. The curator manages conservation and framing and helps visitors who ask to study the collection. Mr Horvitz says that the largest number of them come from France. "You have an obligation to look after it properly. It's part of the cultural patrimony of the world," he says.

Initially, he bought 85% of the collection at auction and 15% from dealers. Now that ratio has been almost exactly reversed: Mr Horvitz's preferences are well known in the trade and the dealers come to him. He prefers it that way to buying at art fairs, for example: "They're for shopping not collecting. Trouble is, people have money but not the time."

He loves French art and he buys it almost exclusively, but it is not his sole interest. "There are many things I could have collected," he says. In the 1980s the subject happened to be French and Italian drawings. Mr Horvitz reports that he now has a new interest. He has begun to collect contemporary Japanese ceramics. "They get me back to modernity," he explains.

(The Art.view column appears every week on Economist.com.)