What is poverty? What does it mean to label people as "poor"? Social scientists tend to reach for the measurable in their definitions. Equating poverty more or less with starvation, the inability to sustain life, they have often calculated the income required for this, and called it the "poverty line". The poor are those who live below this. Critics have long pointed out the many defects of such a view, but the language is nevertheless still in frequent use. And historians have tended to follow the crowd.