Mapping

This is a great map of redlining in the US in 1935 and 1940. They've digitized historical data for large cities.

This super high resolution map of US presidential election results (2008, 2012, and 2016) by precinct is amazing.

It's by Decision Desk HQ which is a pro-Democrat polling and analysis organization with a strong record.

Cross-posted from Energy Justice

I recently updated the Income Layer on Justice Map to use the latest 2011-2015 American Community Survey data.

You can view the data by county or by census tract (roughly 4000 people). While census tracts provide higher resolution that helps us identify areas of environmental injustice, unfortunately the confidence interval is much larger. So there is a lot of noise in the data. If you are looking at the income layer and see a random checkerboard of blue and red - that is noisy data.

As part of this process, I added a Income Change layer that shows the change in median household income between the first period (2006-2010) and a second period (2011-2015).

It is easiest to see the trend in changing income by looking at the counties. The census tract data is even noisier than the regular income data, as the confidence interval is approximately twice as large. However where there are strong trends - like gentrification in DC and Philadelphia you can easily see them at the tract level.

Click on the map to learn how income has been changing in your community!

Change in Median Household Income

In the 2016 general presidential election, the Green party candidates for State Auditor and State Treasurer beat the Libertarians (including the well-known Gary Johnson). But presidential candidate Jill Stein did not fare as well due to strategic voting against Trump.

I live right next to the center of Green Party support in West Philly!

Category Breaks used in the maps: 0.25%, 0.5%, 0.75%, 1%, 1.5%, 2%, 2.5%.
Click on the image for a high resolution one.

A couple months ago I made this property level map of
Philly Housing Age

A couple areas of the city are missing data (in my data source).

I'm trying to make a higher resolution map of median household income. The Census Bureau releases income data by census tract (around 4000 people) and also by block group. Relatively few people use block groups because the confidence interval is too high. Even when you pool five years of data from the American Community Survey the confidence interval for census tracts (which have about 3 times more people than block groups) is high (and can be too high to use).

I made a new map of Philadelphia Exterior Housing Condition using the Office of Property Assessment data (2015).

It is part of a series of high resolution maps I've made for Philadelphia using property level data.

It is interesting to see what parts of the city have new construction, rehabbing, and vacant and/or uninhabitable properties.

I updated Justice Map to use the American Community Survey income data from 2013. So it now uses the five year summary/average of 2009-2013 for the API, when you click on the map, and for the map tile layers. The one exception is Puerto Rico which still uses the old data from 2007-2011.

I made a map of Philadelphia housing prices using the 2014 property assessment data. I use value per square foot as the best indicator of housing quality and demand. If you use total property value - you get large differences that are due to property size. For instance, single family properties vary from 600 sq feet to 3000+.

An estimated 30% of Philadelphia residents have not applied for the homestead exemption which exempts the first $30,000 of a homeowner's property value from taxation. This can save you $402/year if you get the full exemption. The city created this program to take some of the bite out of the property re-assessment (Actual Value Initiative) which increased residential taxes and decreased taxes for the large commercial properties.