Phil Mangess ha hecho un estudio muy detallado de los números detrás del libro de Piketty. Es decir, Magness ha hecho una crítica empírica, otros han hecho una crítica teórica.

La respuesta general de Piketty es que estos errores fueron de tipeo (typos) y que no afectan las conclusiones generales del libro. Este no es el caso, si los números corregidos no muestran una distribución del ingreso como la presentada por Piketty su tesis tiene serios problemas.

Magness ofrece la siguiente reflexión (tomado de su muro de Facebook) que creo describe una postura de la izquierda y el socialismo (y el marxismo) que trasciende al caso de Piketty:

In reading the various responses from Piketty & his defenders, the recurring theme is an insistence that his “general argument” remains intact *despite* the many errors in his data and history (or “typos” as he now calls them). It seems that this retort is completely evading a fundamental burden of conducting empirical research. Consider:

1. Piketty’s “general argument” is that wealth inequality is on the rise, that this is a bad thing, and that we need drastic policy correctives to fix it.

2. The theory behind this “general argument” is that allegedly rising inequality is a product of a capital stock reconstitution that, over time, produces yields for capital-owning rentiers that outpaces income growth.

3. The evidence behind this “general argument” is a series of charts and data sets that purport to show rapidly increasing wealth inequality in the past ~30 years.

Since the validity of the “general argument” – 1 – is dependent upon both 2 and 3 being valid as well, it follows that if *either* 2 or 3 are found to be in error then the “general argument” falls apart.

Several people have drawn attention to reasons why 2 may be invalid on theoretical grounds. Myself, Robert Murphy, Auerbach & Hassett, and a few others have also provided sound reasons to conclude that 3 is invalid as well. Specifically for our part looking at the United States, the raw data that Piketty uses does *not* actually show the wealth inequality trends that he claims. The *only* way he can even get to that claim is by indulging in a substantial amount cherry-picking and chart manipulation to produce a manufactured trend line in accord with his “general argument” and theory. But the raw data, when honestly and fully accounted for, simply does not support his assertion with the confidence and certainty that he claims. It is, at absolute best, ambiguous.

That being the case, does it not follow that Piketty has fallen short of his burden to prove #3? And if he has not proven #3, would this not also deprive his “general argument” of the evidentiary basis it *requires* in order to support the claim of validity that he makes? So to anyone still making the claim that his “general argument” remains intact, I ask this:

On what basis was that “general argument” ever substantiated in the first place?

Bajar el paper de Phil Magness y Robert Murphy de SSRN.