NEW YORK (AP) _ Niall Ferguson, a Harvard history professor and author, apologized on Saturday for saying economist John Maynard Keynes was less invested in the future because he was gay and had no children.

The British-born Ferguson said his remarks at an earlier conference were ``as stupid as they were insensitive.''

During a question-and-answer session after a prepared speech at the Altegris Strategic Investment conference in Carlsbad, California on Thursday, Ferguson was asked to comment about Keynes, an influential 20th century British economist who advocated government spending as a way to make up for lagging demand in an economic downturn.

Ferguson suggested that Keynes philosophy was shaped by his homosexuality. Keynes, therefore, had no children so he wasn't as invested in future generations as others might be, Ferguson said.

The remarks were reported by the website of Financial Advisor magazine and other online publications.

On Saturday Ferguson acknowledged the remarks and said he ``deeply and unreservedly'' apologized.

``I should not have suggested - in an off-the-cuff response that was not part of my presentation - that Keynes was indifferent to the long run because he had no children, nor that he had no children because he was gay,'' he said in a statement in response to an emailed query.

``It is obvious that people who do not have children also care about future generations,'' he added.