Equality Is Efficient: Conversely, you could look at the case of Greg Mankiw who agrees with Lane that redistributive taxation is a bad idea. Mankiw, however, is too familiar with my argument about the inefficiency of inequality and instead argues on ethical grounds that redistributive taxation is morally wrong even though it can improve social welfare. This rather than old arguments about whether the United States should abandon the mixed economy in favor of socialism seems like the real question to grapple with.