By using data from satellites, it is possible to measure the amount of greenery just about anywhere. We did this, and averaged it out within the limits of each city in the Dallas-Fort Worth area. The tree-lined enclaves of the Park Cities rank highly but don't make it into the Top 10. Interestingly, the south side of the Metroplex has some very dense foliage: Cedar Hill and Duncanville, thanks to the green hills adjacent to Cedar Hill State Park that spills over into many of the residential areas.

The "Cross Timbers" cities of Colleyville, Flower Mound, Keller, Denton and Southlake also rank highly thanks to the narrow band of forest, called the Cross Timbers, that results in dense tree growth in these cities.

​On the other extreme, we have cities in more of a prairie setting, as well as those that are newer and have fewer mature trees: Allen, Frisco, Plano, Carrollton, and The Colony. In these areas, most trees are concentrated in narrow bands on flood plains and creeks. To make this analysis fair, we focus on neighborhoods only (with single family homes), we exclude other non-residential land uses, and exclude flood plains.

Showing the greenery index in more detail, we start to see a lot of differences between neighborhoods at a micro level.

We looked at relationships between greenery and the age of the community, as well average home prices.

We expected older neighborhoods to be shadier, since trees grow larger over the years. Typically, neighborhoods start out quite barren after the land is cleared, and new trees planted along roads take time to grow.

Also, we expected certain areas such as the Eastern Cross Timbers to score higher, which is a 15-mile-wide belt of woodland that extends through areas like Flower Mound, Southlake, Colleyville, and Arlington, as shown below.

Higher-priced homes tend to have more greenery, and this is clearest in the Backland Prairie and Grand Prairie areas around Dallas and western Tarrant county, as shown below.

In these areas, we can expect that after a neighborhood has been around a while, it becomes greener. This makes sense as the close-in neighborhoods, which are more expensive, also tend to be the oldest and greenest.

However, greenery is not related to price in the Cross Timbers belts in Tarrant and Denton counties. This is probably because the large amount of natural growth in these areas makes greenery less "special." 

How about cause and effect? Can we conclude that greenery drives price in a meaningful way? No. Proximity to jobs and a whole host of other price drivers are also at work. What is the specific effect of greenery considering a variety of factors? We will explore that in a later post.

Highly granular voting data for the 2016 election was compiled a few years ago and made public online via websites operated by Harvard and MIT. For the first time, this made precinct-level data across the country relatively accessible. "Voter precincts" are fairly small, at about a third of a square mile to one square mile in a typical urban area. But the people living within a given precinct can vary widely. From one neighborhood or subdivision to the next, there are different types of housing for different income levels and family sizes. These differences contribute to different political preferences.

What if we wanted to estimate what is happening at the city block level? You may want to do this when screening blocks that you want to live in, if it is important to you to find the prefect niche for yourself to live where you feel most comfortable. Or, it is valuable for other purposes, like campaign planning. Referring to our favorite diagram, we can see just how much more detail we can get by taking it down to the block level.

Let's get detailed!