For inelastic essential needs (i.e., food, fuel, electricity, water, transportation, toiletries) and high-MPC existence without a commensurate increase in pay,

For inelastic essential needs (i.e., food, fuel, electricity, water, transportation, toiletries) and high-MPC existence without a commensurate increase in pay, this is true. (Longterm decline in wages by inflation in the US). However, the poor cannot buy Ferraris, iRobots, or Toto toilet seats. For discretionary spending portions of high-MPC, there are often bad financial decisions made by the poor to buy overpriced, high-depreciation, low utility, and short lifetime goods and services.