This paper provides a new estimation of an international poverty line based on a Bayesian approach. We found that the official poverty lines of the poorest countries are related to the countries' mean consumption level. This new philosophy is to be compared to the previous assumptions made by the World Bank in favour of an absolute poverty line. We propose a new international poverty line at $1.48 per day (2005 PPP) based on a reference group consumption level. This figure is much higher than that proposed by the World Bank ($1.25 in 2005 PPP), but still within a reasonable confidence interval. By this standard, there are more than 1.7 billion people living in poverty.
