We all know the story: Much of the world is becoming increasingly less equal thanks to the new knowledge economy. Using data from the Federal Reserve Bank of New York, the NY Times (Emily Badger and Kevin Quealy) recently published this interesting piece on "4 decades of inequality" in American cities. This is what the findings look like:

In 1980, the United States was relatively flat in terms of wage inequality (except for maybe Fairfield). In fact, inequality in a place like Binghamton, New York was about the same as in New York City. But thanks to decline in the former and growth in the latter, New York City is now a much more unequal place.

Economic growth is usually considered a good thing, but inequality is not. Emily and Kevin rightly call attention to the fact that -- according to the above charts -- these two things seem to come together as one package. See New York, Chicago, San Francisco, San Jose, Washington, D.C., and so on.

The other takeaway from these charts is the way in which inequality seems to correlate with metro area population. We know that as the population of a city increases it tends to also become more productive. And so what we are seeing here are those urban agglomeration benefits accruing to some, but not all.

There's a lot that can be inferred from these charts.

I spent a good chunk of this morning talking and thinking about underground building details that most people (unless you're in the industry) would never think to consider. This is not a criticism on most people. I mean, I don't know how iPhones are made. I just use and enjoy them. But when it comes to buildings, I'm paid to ask questions and understand how things work.

There's a lot of risk in the ground.

You have to think about things like bearing capacity, environmental contamination (usually), hydrostatic pressure and, generally, how you're going to manage water, particularly if you have a high groundwater table. Usually this last one is about making sure you're keeping the water out. A pretty important detail both below and above grade.

So when I came home tonight and saw the below tweet, I felt obligated to write about it.

If you read the reply from NYC's Metropolitan Transportation Authority, you'll see that this is them testing something they call a "flex gate." It is a flood barrier that allows them to seal off subway entrances in the case of a storm surge and they run these tests (shown above) for 4 hours at a time to make sure they're installed property. This one was.

Managing water is a big part of city building. New York City, Miami, Venice, and countless others know this all too well right now.

The Shed in Hudson Yards has an exhibition on right now called Manual Override. It features the work of five artists. One of those artists is Lynn Hershman Leeson, who is known for exploring the relationship between humans and technology (naturally, she lives in the Bay Area). Her piece at the exhibition is called Shadow Stalker.

The way Shadow Stalker works is that you enter your email address -- a single data point. The installation then pulls up all of the publicly accessible information associated with your email address. Things like your name, age, address, phone numbers, where you were last seen, and more.

She refers to this information as your "digital shadow." It is all of the personal information that is publicly accessible because of the internet. And it is the kind of the information that is already used for things like "predictive policing." Software that predicts where crime is likely to occur.

I am fairly public as a result of this blog. Already this year I have written over 75,000 words. So I can only imagine what the internet knows about me. Probably a lot. But of course, I am volunteering a lot of this information. What does the internet know about us that we didn't explicitly tell it?

If you're interested in learning more about Shadow Stalker, here's a video.