We stand up for a Massachusetts where everyone gets a fair shot, does and pays their fair share, and plays by the same rules.
In May, we posted a graph plotting early education enrollment against 3rd grade MCAS reading proficiency percentages for 50 cities and towns in the state. As a part of our continuing efforts to shed light on the importance of early education, and to gather useful data specific to Massachusetts, we came up with this new graph, which shares the same conceit as our previous one, but uses a narrower sample and a basic weighting system.
Specifically, we looked at cities in Massachusetts. We determined this by finding municipalities across the state that use a “city”-style local government: a mayor who serves as chief executive, alongside a city council, department heads, etc. We added a cutoff to the results of the “mayor-council-etc.” survey, limiting it to only include municipalities with populations above 30,000, about where mayoral-based government is replaced by selectmen or representatives—arbitrary, but necessary to avoid the sample getting out of hand and becoming too broad for our purposes. We therefore arrived at what we have used to define a city: a municipality with a population large enough to warrant a form of local government significantly different from other, smaller communities. We ended up using data from a total of 53 cities from across Massachusetts.
By plotting the early education enrollment percentage in these cities against the percentage of their 3rd graders who tested “proficient” or above on the reading MCAS, we arrive at the graph above. The key thing to notice when comparing this graph and the broader results we published last month is that they look almost identical and have very similar r-squared values. The lack of difference when we control for population does not seem to have an effect on the previously discovered correlation. This means that the correlation between preschool enrollment and reading scores holds across multiple, differentiated samples, which in turn helps us more reliably expect scholastic improvement when enrollment is increased in a wide variety of target locations. Essentially, this chart helps improve the case for a causal relationship between early education and academic achievement that we began to make in our first study.