What is necessary, superfluous and measuring poverty

The goal of this work is to combine the contribution of scholastic philosophy with the technique of poverty measurement in order to clarify how much income should be normatively considered in order to acquire "what is necessary" to live. Scholasticism has differentiated - from Thomas Aquinas - the necessary, socially necessary and superfluous goods. On the first two rights of usufruct property were recognized, but not on the superfluous ones. What the research investigates is whether the absolute poverty line, national or international (currently set at $ 1.90 per day in PPP 2011) gives a good account of the capability to acquire "what is necessary". Once this option is rejected, an Index of Access to the Necessary is proposed and the consequences of public policies that entail the ambiguity of "what is necessary" are analyzed.