There have been some empirical psychological studies, which seem to indicate — you should always be rather skeptical of “studies show… ” until you’ve looked carefully at how the study was carried out and what reasoning the researchers employed — that there is something to this idea of “willpower depletion.” And, this in turn has some implications for those in poverty:
the less money you have, the more situations you will encounter in which you must restrain yourself and make difficult purchasing tradeoffs, and this means you’ll have less willpower leftover later to deal with other situations in which you might need it
