Poverty
The poverty line threshold of $1.90 per day, as set by the World Bank, is controversial. Each nation has its own threshold for absolute poverty line; in the United States, for example, the absolute poverty line was US$15.15 per day in 2010 (US$22,000 per year for a family of four), while in India it was US$1.0 per day and in China the absolute poverty line was US$0.55 per day, each on PPP basis in 2010. These different poverty lines make data comparison between each nation's official reports qualitatively difficult. Some scholars argue that the World Bank method sets the bar too high, others argue it is low. Still others suggest that poverty line misleads as it measures everyone below the poverty line the same, when in reality someone living on $1.20 per day is in a different state of poverty than someone living on $0.20 per day. In other words, the depth and intensity of poverty varies across the world and in any regional populations, and $1.25 per day poverty line and head counts are inadequate measures.
Poverty threshold
Charles Booth, a pioneering investigator of poverty in London at the turn of the 20th century, popularised the idea of a "poverty line", a concept originally conceived by the London School Board. Booth set the line at 10 (50p) to 20 shillings (£1) per week, which he considered to be the minimum amount necessary for a family of four or five people to subsist on. Benjamin Seebohm Rowntree (1871–1954), a British sociological researcher, social reformer and industrialist, surveyed rich families in York, and drew a poverty line in terms of a minimum weekly sum of money "necessary to enable families … to secure the necessaries of a healthy life", which included fuel and light, rent, food, clothing, and household and personal items. Based on data from leading nutritionists of the period, he calculated the cheapest price for the minimum calorific intake and nutritional balance necessary, before people get ill or lose weight. He considered this amount to set his poverty line and concluded that 27.84% of the total population of York lived below this poverty line. This result corresponded with that from Charles Booth's study of poverty in London and so challenged the view, commonly held at the time, that abject poverty was a problem particular to London and was not widespread in the rest of Britain. Rowntree distinguished between primary poverty, those lacking in income and secondary poverty, those who had enough income, but spent it elsewhere (1901:295–96).