Wednesday, March 18, 2015

Price Changes in Consumer Products: Tech vs. Health Care and Education

The graphs were inspired by this tweet from Chris Dixon:

I made the graphs in Tableau using his linked table, and normalized all results by the overall price index to get real prices.

Detractors might argue that the health care price index doesn't fully reflect quality improvements. But high US health care costs are hard to dispute.

There's other great narratives beyond those highlighted above. Notice musical instruments were eight times more expensive in 1929. That fact, combined with cheaper personal electronics, seems to nicely explain popular music in the second half of the 20th century.

Tuesday, March 10, 2015

Mapping Atlanta's Champion Trees

Atlanta's largest tree, center foreground.
The largest tree in Atlanta sits a block from Turner Field at Our Lady of Perpetual Help. The great cherrybark oak is 23 feet in circumference and over 100 feet tall, and shares its space with terminal cancer patients cared for by Catholic nuns. The staff will gladly show visitors their prized tree, old, gnarled, and massive.

Over the past few months, I visited several of Atlanta’s largest trees. This gave me the privilege of viewing incredible trees and tricked me into exploring new parts of the city. The tallest tree in the city is as tall as a sixteen story building, and many of these trees were around before the civil war. While tall, healthy trees may not be the first thing we associate with cities, urban trees are often larger than those in forests. Urban trees are few but can grow both wide and tall while forests trees compete with each other for resources, resulting in tall trees with relatively narrow trunks and canopies. Further, most forests are either periodically logged or only recently protected (relative to the age of a great tree) while some trees in urban parks and on private residences have been able to grow to great size and age due to their protected locations.

The map below shows the champion trees of Atlanta. Champion tree points are a formula found by summing the trunk circumference in inches, the height in feet, and one-quarter of the average crown spread (canopy) in feet. The Atlanta champion tree list contains the local champions of over 100 different species and their close runners up and is maintained by Eli Dickerson, a volunteer with Trees Atlanta. Source data for the list is supplied by Eli and other tree enthusiasts who find and measure large trees across the city.

The map shows that many of Atlanta’s largest trees reside in old Intown neighborhoods on the near East side of Atlanta and in the corridor stretching from Piedmont Park to Atlanta Memorial Park.

Use the zoom controls in the upper left of the map to find your neighborhood, or use the bar graph on the left to click on large trees and show their location and an image for that species.

Let me know in the comments if you visit the champion trees in real life!