Long Term Trends in US Basic Education

The following graphs are from "The Condition of Education 2013", a report from the National Center for Education Statistics in the US. With reforms in education appearing and disappearing as fast as fashion styles, it is useful to look at trends that have stood for a longer time period. There may or may not be a correlation between these trends, but clearly in the past two decades, there are trends that seem to survive.

Preschool Education (Enrollment has been growing over the past three decades)

College Education (Females are completing bachelor's and master's degrees)

Teacher to Pupil Ratio (This has been decreasing over the past fifty years)

The next two figures describe assessments of learning outcomes.

Mathematics Achievement (This has been continuously improving over the past two decades)

Reading Proficiency (This likewise has been improving over the past two decades)

Do the three conditions, early childhood education, higher education of adults (parents), smaller classes correlate with the assessment scores? These data suggest a correlation. Of course, the data neither support nor contradict a cause and effect relationship. Still, one wonders....