There has been lots of discussion on this topic. Many countries have a multidimensional measure of poverty, and there is also an international measure for it (<a href="http:&#x2F;&#x2F;hdr.undp.org&#x2F;en&#x2F;content&#x2F;multidimensional-poverty-index-mpi" rel="nofollow">http:&#x2F;&#x2F;hdr.undp.org&#x2F;en&#x2F;content&#x2F;multidimensional-poverty-inde...</a>).<p>The biggest problem is measuring it, so one standard income-based extreme poverty line makes sense in order to compare across countries.<p>Also, like I said in another comment, this measure of poverty is power purchase parity adjusted, so currency changes should not affect.