The returns to education remain a central concern for development policy. In developed countries there is evidence that the returns to education have been rising. Evidence for changes over this period for developing countries is limited. In this paper we use data from Kenya and Tanzania to...

Our strategy for automatic selection in potentially non-linear processes is: test for non-linearity in the unrestricted linear formulation; if that test rejects, specify a general model using polynomials, to be simplified to a minimal congruent representation; finally select by encompassing...