In New York City
Morgan Alcalay, Ronen Cohen,
Nirothama Datt, Yoon Jung Kim
NYC datamine offers a wealth of information about New York City.
One interesting data set contains information about recycling
rates throughout the five
Careful analysis of this data reveals many interesting facts
about recycling trends. The goals of our analysis was to
determine differences in recycling rate and eco-friendliness across
boroughs, community districts, and income levels, as well as whether
there are any differences in the recylcing
rates of paper (which doesn't have a redemption value) and bottles and
first two pie graphs show the individual city-wide recycling rates
for both paper and bottles and cans. The figures represent
percentage of materials recycled. As you can see, the rate
bottles and cans is 10% higher than it is for paper. We
that this difference is primarily due to the redemption values for
bottles and cans. People have a monetary incentive to recycle
these materials, whereas there is no incentive for paper.
next bar chart shows the differences in average total recycling rates
for each borough. There appears to be a large amount of
- more than 20% - between the most eco-friendlyStaten Island and least
hypothesized that this difference between the boroughs might be related
to differences in income levels. To test this, we first
see whether there is actually a relationship between income level and
recycling rate. To do this, we first joined the community
district and recycling tables, created a query to return community
district, average recyling rate, and median income, and then displayed
the information graphically. The results confirmed our
Return to main page There
appears to be a positive relationship between income and recycling
rate. This relationship can be formally tested with Excel's
regression data analysis tool. The output is reproduced below:
an R-squared of 44.55%, nearly half of the variance in recycling rates
can be explained by the differences in income. The income
variable coefficient means that every $10,000 increase in median income
is associated with 5% increase in the recycling rate.
Finally, we constructed a chart of the averaged median
across boroughs, to see if there is sufficient variance income to
explain the differences in recycling rates.
data roughly supports our hypothesis. Other than the switch
between Manhattan and Queens, the average income graph shows the
boroughs in the same order as in the recycling graph. It is
important to keep in mind, however, that correlation does not prove
causation. Both income and recycling rate might be
affected by a third variable which we have not examined.
used in this analysis can be found at the NYC data mine website.
Two database files were used (and joined for that matter).
The first, Demographic, Social, Economic, and Housing
Community District can be downloaded here.
The second, Recycling Diversion and Capture Rates can be
you want to find out more about community districts in New York City,
please visit the New York City Department of City Planning's website.
More information about recycling can be found at the
Department of Sanitation website.
If you have any questions, please email the authors at:
Yoon Jung Kim