find, these studies take the number considered under the poverty level and derive a number based on households.

So, of the 45 million or so, you could have 15-18 million households (these are fake numbers to demonstrate). Each household could be 1 person to many. This number of households can be characterized as either working or non working. The percentage of working, according to the studies, is higher than non-working.

Since the study is new, I couldn't find any discussion, critical or not. Everything out there is either a direct copy of the BYU press release or the Science article. Neither chose to add a quick blurb about how to calculate that most of America's poor are working. I will add that it appears there is a consensus that this claim is generally true.

Since children and disabled are obviously a huge part of the 45 million in poverty, you can't expect them to hold jobs, but someone within their household does.

For the record, I think it was silly to begin the BYU press release claiming that most poor aren't sitting around on the streets. It makes for a great one liner, but if they aren't willing to add any context about how that can be claimed, don't put it in.