LinkedIn's Sohan Murthy posted a fascinating interactive map showing the most disproportionately common skills listed by LinkedIn users in cities across the US and Europe.
Here's a screengrab of the basic map for the US:
Cities are color-coded based on what skill group most outperformed the nation as a whole. These are not necessarily the most commonly listed skills in each city. Instead, they are skills that LinkedIn users in a particular city listed on their profiles at a much higher rate than users in the US overall. Comparing the local rate to the national rate gives a handy measure called a location quotient that Business Insider has used in the past.
Clicking on a particular city shows a breakdown of the most disproportionally common skills in that city:
Given New York City's status as a center of finance, fashion, and media, the top skills here are not much of a surprise.
Using the legend on the right, you can highlight a particular skill group. The Midwest's manufacturing legacy shows through with disproportionate numbers of people in Midwestern cities listing engineering skills on their LinkedIn profiles:
There's a similar map for European cities as well. Here, location quotients are calculated by comparing city rates to rates for Europe as a whole:
The interactive map, and some further observations, can be found at the original LinkedIn blog post here.