[TelmoMenezes]

The data is objective -- surely not 100% accurate, like most data -- but only interpretations of it can be biased. There is obviously another important variable: the countries' level of development. Very poor countries have low incarceration rates because they don't have functional police and judicial systems.

But you can compare the USA to the rest of the western world: Europe, UK, Canada, Australia, New Zealand. These countries share very similar societies, values, legal systems, forms of government and levels of economic development. With this simple filter the anomaly becomes clear and bias is harder to claim.