This paper incorporates egocentric comparisons into a human capital accumulation model and studies the evolution of positive self image over time. The paper shows that the process of human capital accumulation together with egocentric comparisons imply that positive self image of a cohort is first increasing and then decreasing over time. Additionally, the paper finds that positive self image: ...

We show that restricting a number of characterizations of the complexity class P to be positive (in natural ways) results in the same class of (monotone) problems which we denote by posP. By a well-known result of Razborov, posP is a proper subclass of the class of monotone problems in P. We exhibit complete problems for posP via weak logical reductions, as we do for other logically defined cla...