Well, considering that median household income for the US is $52k/yr, $500/yr is ~1% increase in household income per person, so a ~1-2% effect per household, w

Well, considering that median household income for the US is $52k/yr, $500/yr is ~1% increase in household income per person, so a ~1-2% effect per household, which isn't nothing, even if not astounding. Of course, that's if it were households which earned a median income that received the benefit. Given the correlation between poverty growing up and poverty later in life, it's likely more like a 5% increase per household on the low end of the spectrum, which I would call a fairly strong effect.