 He developed the "Lucas critique" of economic policymaking, which holds that relationships that appear to hold in the economy, such as an apparent relationship between inflation and unemployment, could change in response to changes in economic policy.That led to the development of new classical macroeconomics and the drive towards microeconomic foundations for macroeconomic theory.Lucas developed a theory of supply that suggests people can be tricked by unsystematic monetary policy; the Uzawa–Lucas model (with Hirofumi Uzawa) of human capital accumulation; and the "Lucas paradox", which considers why more capital does not flow from developed countries to developing countries.