Re: DSE 2012 Solutions?

Posted by economist on Feb 07, 2014; 2:59pm
URL: http://discussion-forum.276.s1.nabble.com/DSE-2012-Solutions-tp7584627p7584660.html

See the function is concave as the hessian matrix is negative definite. Concavity implies quasiconcavity , so upper level set is convex. Upper level set is defined as U in the question so answer is b.