Explainer: St. Louis and Crime Rankings

By Ray Closson via fotocommunity.com

St. Louis Arch, Courthouse, and Kiener Plaza

Poor St. Louis. It always gets such a bad rap when media groups decide to rank cities by crime rate. Unfortunately, it’s also not a well-earned reputation. And criminologists are quite vocal about that. The FBI even publishes this Caution Against Ranking with the statistics each year. You can sum up their lack of context and applicability with comments on the data it comes from (the FBI’s Uniform Crime Reports), or the fact that the rankings generalize large, variate cities with a blanket of “dangerous” or “not dangerous,” or that numbers alone provide very little context for a single city’s crime issues. But there’s a specific statistical reason why St. Louis always ends up near the top of these rankings.

Historical Context

St. Louis, the city, was a part of St. Louis County until 1876. At that point, the city seceded from the county. The east border of the city is the Mississippi River, the west border extends northeast from the left-hand edge of Forest Park, north to a point ending at Interstate 270, and south to past the intersection of Interstates 44 and 55. The rest of “St. Louis” is part of the county.

The population of St. Louis city is 320,454 people, according to the 2011 UCR. But that is not the number of people who work and do business in the city. Aside from the usual population of tourists found in any large city, St. Louisans often live in the county but work in the numerous public services, hospitals, tourist attractions, and schools of the city. That’s because the metropolitan area of St. Louis continued to expand well after the secession of the city from the county. With space running out in the city, housing and communities were built in the counties, and to this day those are considered the safer, more family-friendly areas to live. Unfortunately, it’s hard to measure the number of people who work in a city–the Bureau of Labor Statistics suggests in non-seasonally adjusted figures for 2011 that 1,295,000 people were employed in “St. Louis, MO-IL.” I’m not sure why Illinois is included in this number, because once you cross the river, you’re in Illinois and East St. Louis, which is a different city entirely (for the record, East St. Louis has a population of 27,087; the city experienced 1,627 reported violent crimes and 2,176 reported property crimes in 2011. For future reference, that’s 140 incidents per 1,000 residents).

Assuming that a simple majority of those 1.295 million workers are employed in the city, it’s easy to see that St. Louis’ population fluctuates broadly every workday. Residents like myself will tell you as much: on weekends and after 5 PM every day, the city is a bit of a ghost town except near the sports centers and tourist areas.

The numbers that are used to rank St. Louis against other cities with populations greater than 100,000–and which showed St. Louis in the number three spot for 2011–use the 320,454 population number, 5,950 reported violent crimes, and 25,669 reported property crimes. That’s 98.7 incidents per 1,000 residents, but there’s no way to separate crimes against non-residents and measure crime per, say, 1,000 individuals present on an average day within the city limits. (The “per 1,000” device is one used often in criminology to quantify crime relative to population.)

It’s worth mentioning that St. Louis isn’t the only city that suffers from this statistical complication, and also that metropolitan area rankings often rank St. Louis far below the top 10 “high-crime” cities. Here are some more details that should make you think twice before writing a ranking.

Index Crimes and Chicago

The FBI’s UCR includes totals for reported crimes under a grouping known as the index crimes. These are four violent crimes and four property crimes used as benchmarks for change over time: murder, aggravated assault, forcible rape, robbery, grand theft auto, arson, burglary, and larceny. Unfortunately, not all police departments report or tally these in uniform ways. As a result, you can see a little footnote at the bottom of all UCR tables indicating that rape statistics for Chicago and the state of Michigan are not recorded the way that the FBI requests.

Reported and Dark Figures

I preface the number of crimes for each category with the word “reported” because journalists need to keep in mind what the UCR actually measures: complaints to the police. This is not an indication of the number of people arrested or convicted of crimes, or the total number of convictions. While that would make you think that these would be overestimates of quantities of crime, also keep in mind the criminological rule of thumb: only half of all crimes are reported, in general. The other half, the unreported crimes, are referred to as the “dark figure” of crime. The most frequently cited campaign to quantify unreported crimes is the National Crime Victimization Survey, a telephone survey of random residents across the United States about their personal experiences with crime. Because this data is not meant for geographical comparisons and trends, it is tallied on the national level, not by state.

Better Stories with UCR Data

Even if you decide that you really don’t want to do a ranking with UCR data, that doesn’t mean you can’t use the numbers at all. There are some great stories lurking in the data for a local crime reporter that your readers can really use.

  • Assuming that your city’s police departments report crimes the same way year after year, this data is very reliable for measuring city-wide trends. Keep in mind that, nationally, crime rates have declined every year for more than two decades–and no one knows why! It’s the great criminological mystery, so be prepared to see your city’s crime rate has been falling as well.
  • The same report featuring the UCR numbers also features numbers for arrests by region and police employees by region.
  • Add to that numbers for hate crimes and police officer injuries and fatalities. Again, it’s more reliable to frame these in comparison to past and future numbers, not in comparison to other regions or cities.

One more thing to note: these numbers are only as accurate as you are cautious. Review methodologies, footnotes, and editor’s notes before deciding how you want to display the data, to be absolutely certain that you are not misrepresenting the numbers.

(I’ll add that, thankfully, the publication I linked to above for ranking St. Louis third in high-crime cities published this article later the same day to add context and caveats to the data, some of which I mentioned above.)

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Data Project: Scraping OSHA Inspections

ScraperWiki's logoOne of the most challenging–yet most rewarding–projects I’ve completed for the Engineering News-Record was the building of a PHP scraper using ScraperWiki. It’s a free service for data liberators to build scrapers in PHP, Ruby, or Python that update automatically and are hosted on ScraperWiki’s servers.

I’ve built a scraper to pull construction industry inspection records from the OSHA database. The resulting dataset records some interesting things: the companies with the most violations, for example.

This was my first time handling PHP. Luckily, there are abundant tutorials and tips available on the ScraperWiki website, and an understanding of another coding language helps.

It stands to be a great resource for ENR and could be valuable for any industry-centered magazine. And I invite anyone to explore the data or use my example to create a scraper for OSHA inspections of a different NAICS code. All you have to do is change the associated NAICS code in the URLs to scrape (23 is construction) and adjust the number of times it scrapes in the loop.

If you have a data set you would like scraped, I can help you build a scraper, or you can send it my way! I’m always looking for new and newsworthy data to mine. Ideal data for an automated scraper is too large to copy and paste and displayed in a uniform format online.