... of new knowledge. There is no constraint on the range of θ. If past knowledge offers the necessary foundation upon which to discover new knowledge, then θ is positive. On the other hand, it ... deride the theory as flawed; rather, they claim its general form is too broad to address difficult institutional and country-specific issues of underdevelopment that are challenging to formalize.71 ... for these concerns, they find a rate of return to schooling of 10.6% in 1985 and 7.0% in 1960 – the former comparable to the 9.9% average return to schooling found in 39 Heckman, James and...