The report’s conclusion is about the dropout rate in all Center City schools, not just in high schools. By asking respondents if they graduated high school, the survey does take into account instances of dropping out that occurred before high school.

This isn’t the flaw because, even if some residents did complete their high school work in less than four years, they still graduated high school.

The report’s conclusion is about the dropout rate from Center City schools, but it never establishes if its survey respondents actually attended Center City schools. Perhaps many of them dropped out of schools in other cities and then moved to Center City.

The report’s conclusion is simply claiming that Center City schools had one of the highest dropout rates in the country. It doesn't need to predict any future effects of this information.

The argument never addresses the value of a Center City high school diploma, nor does it need to. It’s simply arguing that Center City schools have a high dropout rate.