THE NEW YORK 'Smart Set' (aka the 'Social X-Rays' or the 'Ladies Who Lunch') may be unlikely contributors to the caring, sharing mood of Democratic Clintonism. But share they do. For while it is no longer chic to dress up and go out, it is ultimately stylish to buy clothes, stay home and donate the clothes one would have worn if one had gone out to a thrift shop benefitting a charitable cause.

At these uptown Manhattan shops, those who are so out of tune with the stay-at-home mood of the moment that they still yearn for a baby-pink leather Chanel jacket to go out in can pick one up for a song.

At the Irvington Institute Thrift Shop, which benefits research on Aids, cancer and diabetes, you could choose last week from a YSL satin swing coat, a Calvin Klein beaded shift and several frocks from Valentino. Prices started at dollars 50. The only problem is that no Social X-Ray is ever bigger than a size 6.

Nan Kempner, probably the most famous of the Park Avenue couture shopping set, says that she donates her tiny cast-offs to the Memorial Sloane-Kettering Thrift Shop, which benefits the eponymous hospital. Mrs Kempner gives till it hurts. 'I believe the lucky should give back. But I hate to do it. I just know whatever I give will be just what I'll want to be wearing again,' she says.

Mrs Kempner also gives to the annual Posh sale, which benefits the blind. Tiny Nan-sized women wait in line for the couture cast-offs which she loaths parting with so much that she says she is tempted to dress up as someone else and join the queue.