Emojis of Pittsburgh

by Dan Tasse and Jennifer Chou

What do people in Squirrel Hill talk about?

Or, more interestingly, what do people in Squirrel Hill talk about that people in other neighborhoods don’t? What is it that makes Squirrel Hill Squirrel Hill? That’s the question we set out to answer with this project.

words

Most frequently tweeted words in each Pittsburgh neighborhood

How it works

We gathered all tweets geotagged in Pittsburgh over about a year, from December 2013 to January 2015. We sorted them by neighborhood (using boundaries provided by the WPRDC) and used a modified TF-IDF algorithm to figure out what words were specific to each neighborhood. This algorithm counts the frequency of a word in a given neighborhood, and then adjusts the word’s final score based on how many other neighborhoods also use that word.

For example, “Steelers” is used a lot in Squirrel Hill, but it’s also used in many other neighborhoods, so it has a pretty low score. “Tunnel”, however, is quite popular in Squirrel Hill (mostly due to people grousing about tunnel traffic), but not elsewhere. Similarly, “10a” is a popular bus used to get around Pitt, but isn’t used elsewhere, so “10a” shows up a lot in Oakland.

10a

Tweets referencing the “10a” bus

An emoji is worth…

These words just represent what people are talking about on Twitter. What are people feeling? To answer that question, we looked to the emojis people are tweeting. Emojis are an interesting new form of communication: one character can often say more than a word, so they can tell us about where people like to do certain things, or maybe even how people feel.

emojis

Top emojis in each ‘hood

For example, we can see that the zoo is up in Highland Park, and that people like watching baseball and football and drinking beer on the North Shore. Obvious enough. But did you know how popular the swimming pool in Oakland is, or the Christmas tree lighting downtown?

Future work, and so what?

There’s still work to do, of course. One major challenge is algorithmic: How do we combine these posts from multiple people into a representative aggregate? A lot of these words/emojis are boosted by one person tweeting them multiple times. We don’t want one person to dominate the neighborhood’s tweets, but we do want an avid basketball fan to count more than someone who just tweeted about basketball once.

We hope this is the first step towards useful neighborhood guides. Imagine if you were moving to Pittsburgh for the first time, and looking for the right area to live in. Knowing that Squirrel Hill South has a lot of basketball fans, or that the top words in Lawrenceville are trendy bars or music venues, could really help you get a feel for the city and its many unique neighborhoods.

Try it out! http://emojimap.herokuapp.com

(Be patient; it’s on a free server so it’ll be a little slow.) And send any feedback or ideas to dantasse@cmu.edu.

Dan Tasse is a PhD student in Human-Computer Interaction at CMU. He’s interested in how we can use social media posts to help people understand their cities and neighborhoods better.

Jennifer Chou is an undergraduate studying Computer Science at CMU.

Why did Pittsburgh survive the housing slump?

by Nick Kharas and Emily Sasse

The Stability of Pittsburgh’s Property Market

Pittsburgh is known to have one of the most stable property markets in the United States. The city has not had a housing recession. It is safe from housing bubbles for a few reasons:

  • Land Value Tax – Historically, Pittsburgh’s taxation policies encouraged productive land use and steadied its housing market. The city taxed the value of land at a higher rate, and the value of buildings and improvements at a lower rate. Productive investors could maximize their after-tax return on investment, while speculating on idle land was not lucrative. However, this split-rate tax was discontinued in 2001.
  • Available Space – Unlike larger cities, Pittsburgh is not constrained in building space or in growing outward.

It is important to note that there has been a drop in property value in recent times. Home values have fallen over the last year. However, this does not yet indicate that there is a bubble in the property market.

  • Owners of high-quality real estate want to hold on to their property and not sell. Additionally, lower interest rates since 2010 encourage owners to hold on to low mortgage rates.
  • According to Mr. Hanna of Howard Hanna Real Estate Services, first time buyers are finding it hard to get a mortgage, and millennial buyers who want to be flexible and not be in Pittsburgh forever will not want to buy real estate in the city.
  • Home values are down in some neighborhoods, but are rising in neighborhoods like Lawrenceville. This is primarily because of the thriving restaurants, shops and jobs in the east side of the city.

To validate these views, we analyzed Pittsburgh property sales over the last four years (January 2012 to November 2015) found on the WPRDC open data portal. We can see that a majority of the property parcels involved in transactions are owned by individuals rather than corporations. This can give us a good indication of the housing market in Pittsburgh.image1We also decided to look at the changes in the median property values in Pittsburgh over the last four years. We selected the median instead of the mean, as there are a few transactions in 2012 and 2013 with extremely high property values, and these outliers are adding unwanted bias to the average property values. Thus, the median is a good indicator of the common trend in Pittsburgh housing.

image2

The data does seem to support the points mentioned already. In 2013, the median property value rose by only 6%, while in 2014, we noticed a negligible fall by 0.31%. This does indicate the stability of the city’s property market. Also, we do notice that the median property value has fallen by about 10% in 2015. However, it does not give sufficient evidence to conclude the presence of a real estate bubble in the city.

In parallel, we also decided to check if the federal rates (retrieved from https://research.stlouisfed.org/fred2/series/FEDFUNDS#) were having any impact on Pittsburgh’s real estate market. We found that there was no statistically significant correlation between both. We calculated the below figures to reach our result:

Correlation Coefficient -0.16
Significance test – p-value 0.25

The probability of the property values being correlated to federal interest rates by chance rather than statistical significance is less than 0.25. For the correlation to be statistically significant, this probability should have been less than 0.05.image3

Next Steps

This project focuses on property sales in Pittsburgh. Going forward, future work involves continuing to monitor property sales and relevant indicators in the county, to determine whether or not current and historical trends continue. This will enable informed and successful future policy decisions.

In addition to Pittsburgh, it would be interesting to extend this research to Allegheny County and surrounding counties, or the nation overall. This type of analysis would provide key insight into the Pittsburgh real estate market. It would reveal the performance of the Pittsburgh real estate market in comparison to real estate markets in similar cities across the United States.

 

Nick Kharas is pursuing a Masters in Information Systems Management at Carnegie Mellon University. He has a deep focus on emerging technologies in business intelligence (BI), advanced analytics and data science. Prior to this, he was a data warehousing professional at a Japanese multinational financial holding company. When not a data nerd, he enjoys travelling or just meeting new people. You can connect to Nick at https://www.linkedin.com/in/nickkharas

Emily Sasse is pursuing a Masters in Public Policy and Management: Data Analytics. During her time at Heinz, she has developed a keen interest in the study of business intelligence and data analytics. After graduation, she will join Accenture as a Digital Consultant in Boston, Massachusetts. Emily enjoys winter sports and exploring the east coast. You can connect to Emily at https://www.linkedin.com/in/emilysasse

The original project also had active contributions from Sridevi Yagati Venkateshdatta, Ranjani Padmanabhan and Jingwei Cao.