It plays on and invokes the oft-cited statistics about graduation rates and reading. Seems simple enough...if Billy can't read by 3rd grade he has a much higher chance of dropping out than William, who can.
The story and the causal relationships embedded therein are complicated, though. Statistically, the correlations work, but discerning causality within those correlations is more tricky.
The presumed causality represented in that picture is that if we make sure Billy can read by 3rd grade, his chances of graduating will become much higher. Education being a complex process, though, Billy's learning to read by 3rd grade is only part of the story. For instance, the number of "sample" children in the picture would likely be similar if we were creating a claim about being underfed.
"One of these (3?, 4?) children won't graduate if they're underfed."
The point is that many factors going into "graduating," which implicitly stands in for "gets educated" in this claim. Reading is no doubt critical, but many factors contribute to the process called "learning to read," and it's just possible that some of them are (chrono)logically prior to "reading by third grade."
In other words, just relying on a connection between Billy's reading by third grade and his graduation assumes a host of prior and subsequent factors that we need to be more careful to consider.
Imagine this scenario. Billy is behind in his reading in second grade, for a wide variety of reasons. Some sort intervention program gets him caught up in third grade, so that he is "reading" by third grade. We changed the story, as the billboard says.
But the story is hardly over. Quite likely, the reasons that Billy was behind in 2nd grade are still present. He's underfed (i.e., he lives in poverty, which has lasting effects on educational performance), he lacks educational support outside school, his family circumstances distract and distress him, or a combination of all 3 (and others).
Billy may find that he routinely slips behind. In fact, school has not been a particularly pleasurable pursuit (at least not academically), so he neglects it. If reading and "schooling" more generally are not supported and encouraged (we have to have signs like the one above because education competes with a lot of non-educational social impulses in our culture, after all), Billy may well retain his disinterest in school, even though he was able to "read" in 3rd grade.
What is "reading by 3rd grade" after all? Even the best 3rd grade reader would be woefully unprepared for education or life if their reading abilities remained at 3rd grade level permanently. So the claim on the poster seems to presume that if we could just make sure children can read by third grade everything else thereafter will happily?, comfortably?, reliably?, automatically?, effortlessly? fall into place.
But if Billy struggled for 3 years prior to finally "getting it," school may have become an unpleasant enough process that he will forever have a distaste for it. Getting caught up in his reading may not unlock the necessary enthusiasm, commitment, organization, etc., required to successfully do the remaining 8 years to graduation.
And what is "graduate"? Some day, people will realize that the markers we've established as proof of "education"--both that earned by students and produced by schools--are beyond dubious, they're ridiculous. "College and career ready" is a shibboleth, and probably more than traditional high schools can do. (More on that some other time.) The curtain to pull back today, though is the one that hides the fact that "graduation" and "college/career ready" play out very differently in high schools.
I'm not sure exactly why people don't realize that when you incentivize principals, teachers, schools to improve their graduation rates you will cause them to scramble to get students graduated by whatever means they can. As more than one high school colleague has told me, "We bend over backwards to get these kids to graduate." And that often includes so-called credit retrieval programs that aren't exactly the regular course of school study. But as long as people don't take too close a look at what those programs are, and whether they actually give any kind of worthwhile education to those students who use them, we can all be proud of our increasing graduation rates.
Please don't misunderstand....you should go volunteer somehow to help the Billys of the world do better in school. Because education is an arduous, sloppy, time-consuming process. It's going to be more difficult than the advertisement makes it appear.