Isolated Schools Clustered by Test Scores, Family Income

If one looks at the San Francisco Unified School District as a whole, a clear pattern emerges: Schools with the highest level of achievement tend to have the lowest levels of family poverty. And schools that are identified as “racially isolated” are visibly clustered by both income and achievement. This plot shows the base Academic Performance Index for each school in the district for which data are available, as well as the percentage of students poor enough to qualify for free and reduced-price lunches, which are used as a proxy for measuring poverty.


Ranking Schools by Diversity

Schools across San Francisco show markedly different levels of racial and ethnic diversity. Increasingly over the last five years, schools are dominated by one racial group. With mathematical tools, it is possible to measure which schools are the most and least diverse. We chose to rank schools using a formula that economists use to tell whether an industry is dominated by monopoly ownership, the Herfindahl-Hirschman index, also known to ecologists as the Simpson diversity index. The idea is the same: Sum up the squares of all the fractions of your sample. The higher the number, the lower the diversity.


KQED Tackles Junction Between Homelessness, Mental Illness

KQED Public Radio’s “Forum” hit the airwaves this morning with a conversation with Robert Okin, the former chief of psychiatry at San Francisco General Hospital, who recently published a new book on homelessness and mental illness. He said the common belief that the homeless choose to reside on the streets, from his experience profiling them, is false.