Especially check out some of the research they have done which addresses some of the questions in this thread:
<a href="https:&#x2F;&#x2F;www.givedirectly.org&#x2F;research-at-give-directly" rel="nofollow">https:&#x2F;&#x2F;www.givedirectly.org&#x2F;research-at-give-directly</a><p>direct link to paper:
<a href="https:&#x2F;&#x2F;www.princeton.edu&#x2F;~joha&#x2F;publications&#x2F;Haushofer_Shapiro_UCT_2013.pdf" rel="nofollow">https:&#x2F;&#x2F;www.princeton.edu&#x2F;~joha&#x2F;publications&#x2F;Haushofer_Shapi...</a>