“Over the past two decades, the Impressionist and modern art market has seen demand reach dizzying heights and then collapse, and supply fluctuate from feast to famine. But last week it had a solid, confident air as buyers spent almost £165 million at Christie’s and Sotheby’s main New York sales. Helped by a bumper crop of estate sales and the controversial decision of several American museums to sell works to fund new purchases, there was plenty to tempt buyers, who reacted enthusiastically.”