Saturday, April 30, 2011

Student Instructional Hours

The Chicago school year is 174 days with 5.75 hours per day, for a (rounded) total of 1001 instructional hours per year.  The New York City school year is 186 days with 6.83 hours per day, for a (rounded) total of 1271 instructional hours per year.

The cumulative difference is striking, and is graphically depicted below (click to enlarge).  By the time a New York City student has graduated, while being in school for 12 years, they have effectively been educated for 16.51 Chicago school-years.  Prima facie, a remarkable disparity.  


  1. I was talking with some teachers about a similar issue yesterday. Four teachers from four different Chicago schools had different amounts of classroom time. However they all had similar curricula. The result was that the teacher with the most classroom time finished the entire curriculum and had extra time which he filled with fun activities and said he could teach the same material slower or take more days off during the year for non-curriculum stuff. The teacher with the least classroom time said he had to cut out the least important material and cut down on fun days. Cutting out the least productive days for schools with less time and adding less productive days for schools with more time might suggest that actual learning benefits are less stark that the picture above.
    However, if New York just has a longer curriculum and can stay equally productive over time then you would expect amount learned to look like the graph above.
    I would expect classroom time might exhibit some diminishing returns to number of days in school but I would assume someone has looked at this.

  2. I agree that this is incomplete evidence, and your point is good--I imagine test scores of Chicago seniors (including dropouts) wouldn't be four-and-a-half-years worse.

    Of course, having "fun time" or "slower learning" may cause lower dropout rates--it's not clear that teachers actually know what's important, and I could believe that the "unimportant" fun stuff actually decreases dropout rates. Similarly, there may be increasing returns to scale because the initial cost of startup for every class (settling down) is amortized over longer periods, just as fixed costs for firms are amortized by larger production runs. (This is just to say that the direction of bias is unclear).

    The impact on crime might be interesting, however. An extra hour-and-change to be mal-socialized and commit crimes outside of school might be significant over a lifetime. (As compared to a slightly more structured mal-socialization). I also imagine that not all that extra time is spent learning.

    All that said, the simple difference was truly astounding to me...four and a half years of "education."