Hummer also won't work if you apply it in a wrong way, thus to make economic theories work - just study and understand it up to adequate level... at least consider limitations as 'ceteris paribus' .. etc... In general - economic theories are not 100% predetermined rules - it's more stochastic with defined by theory probability of outcome more than ~70% (sometimes, but often even P>50% is enough) ... there are also hypotheses rather than theories... screwed implementation of these theories - is another story..Quote from Onlygold:Economic Theories don't work
All in all economics is humanitarian/social science, and as society changes (or on psychological level, individual reaction/rationale) - so economic theory should be adjusted for such changes.