Baltimore 2010 Census Results by Race

The 2010 Census results for Maryland are out, time to start the comparisons!

(data sources: QT-P5 data series for the 2000 census; P1-Race data series for 2010 census, note that if you follow the link you have to sort the table for Maryland counties)

Baltimore City lost population between 2000 and 2010. Not unexpected, although slightly worse than optimists (notably in city hall) expected. Overall Baltimore City is now home to 620,961 people, down 4.6% from 2000.

When that's broken down by race, here's how the changes from 2000 to 2010 look:

Now, replace an "i" with an "oun" and look what happens:
Interesting stuff. Baltimore County grew by 6.7% from a larger base, so the combined total population for Baltimore City + County increased. Interestingly, the proportion of census respondents listing their race as "White only" decreased in both Baltimore City and County! In fact, combining the two areas shows that "White only" has dropped from being a slim majority of respondents (54.6%) to a plurality (49.4%).

Looks like there are a lot of other interesting trends too. The more than doubling of "Some Other Race Only" as a response, the dramatic increase in respondents stating "Asian Only" in Baltimore County, and (of course) the huge increase in those claiming more than one racial heritage. Plenty more interesting data mining ahead.

In case you want to check out the data in tabular form:

Baltimore City Census Results
Race	2000	2010	Change
White alone	205,982	183,830	-10.8%
Black alone	418,951	395,781	-5.5%
American Indian or Alaska Native alone	2,097	2,270	8.2%
Asian alone	9,985	14,548	45.7%
Native Hawaiian or Other Pacific Islander alone	222	274	23.4%
Some other race alone	4,363	11,303	159.1%
Two or more races	9,554	12,955	35.6%
Total:	651,154	620,961	-4.6%
Race	2000	2010
White alone	31.6%	29.6%
Black alone	64.3%	63.7%
American Indian or Alaska Native alone	0.3%	0.4%
Asian alone	1.5%	2.3%
Native Hawaiian or Other Pacific Islander alone	0.0%	0.0%
Some other race alone	0.7%	1.8%
Two or more races	1.5%	2.1%
Baltimore County Census Results
Race	2000	2010	Change
White alone	561,132	520,185	-7.3%
Black alone	151,600	209,738	38.3%
American Indian or Alaska Native alone	4,616	2,625	-43.1%
Asian alone	26,912	40,077	48.9%
Native Hawaiian or Other Pacific Islander alone	242	319	31.8%
Some other race alone	4,685	12,801	173.2%
Two or more races	5,105	19,284	277.7%
Total:	754,292	805,029	6.7%
Race	2000	2010
White alone	74.4%	64.6%
Black alone	20.1%	26.1%
American Indian or Alaska Native alone	0.6%	0.3%
Asian alone	3.6%	5.0%
Native Hawaiian or Other Pacific Islander alone	0.0%	0.0%
Some other race alone	0.6%	1.6%
Two or more races	0.7%	2.4%
Baltimore City + County Totals
Race	2000	2010	Change
White alone	767,114	704,015	-8.2%
Black alone	570,551	605,519	6.1%
American Indian or Alaska Native alone	6,713	4,895	-27.1%
Asian alone	36,897	54,625	48.0%
Native Hawaiian or Other Pacific Islander alone	464	593	27.8%
Some other race alone	9,048	24,104	166.4%
Two or more races	14,659	32,239	119.9%
Total:	1,405,446	1,425,990	1.5%
Race	2000	2010
White alone	54.6%	49.4%
Black alone	40.6%	42.5%
American Indian or Alaska Native alone	0.5%	0.3%
Asian alone	2.6%	3.8%
Native Hawaiian or Other Pacific Islander alone	0.0%	0.0%
Some other race alone	0.6%	1.7%
Two or more races	1.0%	2.3%

I'm Still a Nerd

Long ago, when I was new to blogging, I commented that I was a huge nerd because I decided to plot my car mileage vs time. I never stopped being that nerd, now I just have a much larger sample size.


My car mileage is still fairly linear, but you can see that there has been a slight change in the slope over the last couple years. (You can also see that I got really bad about getting my car in for regularly scheduled oil changes in the late 2008, early 2009 timeframe, but let's not focus on that.)

Looking back at the data, I can see that between January 2005 and January 2008 I drove approximately 44,000 miles. Admittedly, I did drive a huge road-trip one Christmas (nearly 4,000 miles in less than two weeks), but that's still averaging just under 15,000 miles per year. Over the more recent 3-year period (January 2008 to January 2011), I drove only ~35,000 miles. The funny thing is, I've actually increased my commute distance by a couple miles per day since June 2008. How am I driving less?

I think the big change is that in June 2008 I moved close a train station that allowed me to occasionally take commuter rail to work instead of drive. Nowadays I can also take the light rail or bike to the train station. I have also, over the last few years, become a big fan of new urbanism, walkable neighborhoods, and public transit (I've always been a fan of biking places if possible). Also, more recently, I've moved in with my girlfriend and now make her drive me places sometimes because car pooling is more efficient or I'm planning to drink alcohol (or I'm feeling lazy and talk her into driving). Also, this last fall I had a problem with a bent wheel that I procrastinated on fixing because I didn't want to pay all the money since I knew I needed tires anyway.

All of this combined means that I drove around 11,300 miles in calendar year 2010. That's about 2,400 less than I drove the first 12 months I owned my car!

Finally, in what is definitely a miracle of Honda engineering, my car continues to get around 30-32 mpg on average. So by those numbers, I'm saving myself 75 gallons a year which was probably worth between $150 and $225!

Finally, in a particularly ironic turn of events, in my 2007 blog post on my driving I was pissed off to learn how much of my gasoline costs went to taxes. Now, in 2011, I've educated myself a lot more about transportation funding/policy and I've seen some income growth while inflation has been nearly non-existent. As a result, I'm now a huge fan of raising taxes on gasoline in Maryland (since the gasoline tax is not indexed to inflation and has not been increased since 1992), especially if its used to fund effective public transportation, bicycle transit improvements, or improve run-off control from existing highways.

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By the way, the latter part of the last decade was actually a period of time in which the US was becoming less car dependent. Some group called The Center for Clean Air Policy released a study that included a chart showing that from 1960 into the mid-90's GDP growth and growth in vehicle miles traveled (VMT) tracked each other almost exactly. But around 1995, the two started to diverge, with GDP growth outpacing the growth in VMT. Very, very encouraging news! Good blog post with commentary from the New York Times.

Baltimore Murder Charts - Year End 2010 Edition

I haven't been the best at updating my blog recently, but one of the few original things I post regularly are charts covering Baltimore murders. My sources remain Murder Ink from the City Paper and the Baltimore Crime blog.

Murder trends for 2010 were not nearly as exciting as 2009. Murders declined again, but not by a large number. Most of 2010 looked like 2009, the main exception being that there were far fewer deaths classified as homicides due to prior year murders. As I've been doing, any homicides classified due to an act in a prior year are counted in that prior year (by going back and editing data). So using this methodology I get slightly different numbers than the official tally, but I think it's better for tracking trends.

In 2009 there were officially 238 murders in Baltimore, but 14 of them were due to acts of violence from prior years, so I count that as 224 murders. In 2010 there were officially 223 murders in Baltimore, but 4 of them were due to acts of violence in prior years (none of them from 2009 though, so no upward modification). So while the official numbers drop from 238 to 223 (a 6.3% decrease), my count drops from 224 to 219 (a 2.2% decrease).

Still, we've come a long way since 2007. The 2010 total is down 20% from 2007. The improvements are pretty obvious when you look at the homicides by month and the cumulative plot of homicides for the last four years.



In fact, 2007 was such a higher total than 2008-10, it's actually better to remove it to compare the more recent years.


So what do we have? Looks mostly like stability. Sure, from 2008 to 2010 there were about 14 fewer homicides in Baltimore, a total of a 6% decrease. Not terribly impressive, even if murders continue decreasing at this rate we'll have to wait until 2017 to see murders become something that happens only every other day. That's not a terribly cheerful prediction. Hopefully the continued focus on reducing illegal guns in the city will continue to lower shootings and homicide rate will drop faster.

It needs to. Baltimore's per capita murder rate remains one of the worst in the country. At 35 per 100,000 (my math based on 223 official murders and U.S. Census estimated population for 2009). However, if you are African-American in Baltimore the per-capita murder rate is unbelievable. According to Anna Ditkoff of Murder Ink, 90.6% of 2010's murder victims were African-American. Based on Baltimore's demographics, this indicates that African-Americans in Baltimore face a 50 per 100,000 per capita murder rate while residents of other races experience a 9 per 100,000 per capita murder rate. To put that in perspective, residents who are not African-American are safer in Baltimore than the average Albuquerque resident (source: Wikipedia article on crime in US cities).

Finally, my favorite chart that I create for tracking murder trends:


Vertical axis magnified:

Links to previous year's homicide summaries:
2009 Year End Summary
2008 Year End Summary

Baltimore 2009 Homicides - Everyone CALM DOWN

So the opinion in this town seems to be that Baltimore had 238 homicides in 2009 compared to an official 234 in 2008. Nationally homicides decreased in 2009. DC was way down this year. Quick, everyone panic!!

Bulls&%*.

In 2009 we had 14 prior year homicides. That means that 224 people died of injuries sustained in violent incidents in the city of Baltimore in 2009. 4 of those 14 prior year assaults occurred in 2008. Baltimore logged around 140 fewer non-fatal shootings in 2009 than 2008. As much as critics and "The Wire" fans would hate to admit, the homicide rate is lower and this city is safer than it has been in a generation.

The Baltimore Sun ran a very good series of graphics on what homicides and shootings looked like in 2009. The Sun shows that in 2009 there were around 450 non-fatal shooting in the city. While you might be like "DAMN!", if you look at the graphic you'd realize that only 2 years ago there were 652 non-fatal shootings. That's an incredible drop over a period of only 2 years. This whole "fight against bad guys with guys" that Bealefield is always on about seems to be making a difference. Frankly, given the level of non-fatal shootings, I'm shocked we managed to make it up to 238 for the year.

Actually, that's where homicides due to prior year assaults comes in. As I stated in the intro, Baltimore racked up 14 CY2009 homicides from prior year assaults. That's a lot. Per my research of the Murder Ink archives, we had 5 prior year homicides in '07 and 6 in '08. 14 is a big deal and it skews the real measure of how deadly the city was last year. In 2007, when the city record an official 282 homicides, 5 were a result of prior year result, which is about 1.8% of homicides. In 2009, we have 238 official homicides and 14 prior year assaults, which is 5.9% of homicides.

What this calls out for, no, cries out for, is someone to track homicides based on the date of the assault! Thankfully, I am willing to do this. I've carefully researched Anna Ditkoff's Murder Ink and the BaltimoreCrime blog posts. I've spent time auditing my numbers. Lots of time. My girlfriend has been frustrated by the time I've spent on this. But I've got your answer.

Discounting prior-year assaults, there were 279 murders in 2007, 232 murders in 2008, and 224 murders in 2009 as of the first week of January, 2010.

"But," you might say, "I don't understand! You said there were 282 murders in 2007 with 5 as prior-year assaults, so why is your total 279?" The answer is that I'm keeping a master spreadsheet. So if someone died in 2009 due to an attack in 2007, I go back and add the murder to the date in 2007 when the victim was attacked.

This master spreadsheet allows me to track a number that I call "Trailing Twelve Months Homicides". This statistic does not appear to be tracked anywhere else, but I think it matters. Restarting the homicide count every January doesn't show you how you're really doing. If you start counting every January, by March you're comparing 33 murders to 30 and coming up with a 10% increase in homicides when really it was just a couple bad weekends. There aren't a lot of homicides, really, so the data is really noisy and needs to be considered over at least a 12-month time period. So I think that Trailing Twelve Month Murders really makes sense.

So, without further ado, here's the plot of Trailing Twelve Month Murders from January 1st 2008 to approximately the present:

(Click on the chart above if you want to a better view of it, Blogger doesn't do a real good job with graphics sometimes)

Anyway, look at that graph for a minute. It shows that two short years ago the Baltimore murder rate was around 275 for the past 12 months. Today it's sitting much closer to 225. Back in mid-2008 we dipped below 215 per 12-month period before jumping back up to around 230. Most of '09 held steady around 230 (the 30-day moving average never got close to 250 for all of 2009). During the fourth quarter of 2009 the murder rate started slowly sliding downward. By the end of the year Baltimore was doing better than we had since 2008.

Why didn't you know this already? Because around Thanksgiving the ME's office started owning up to all the people that died this year who should be classified as homicides but were actually assaulted in a previous year. Ok, maybe it wasn't the ME's office. I actually have no idea who actually "owns up" to those statistics, but the point is that it hit us hard in December. Between Thanksgiving and the end of the year we added 8 prior-year assaults to the '09 homicide tally. So right as everyone started paying attention to the annual total, it jumped for an external reason. Prior-year homicides took December from a total of 19 homicides (about average for 2009) to 25 (a pretty bad month for 2008-09).

So the moral of this story is that Baltimore is on the right track. We're holding steady against last year (the best year for homicides in two decades) and even if we hold steady on new attacks, we're likely to drop the total. Non-fatal shootings are basically the feeder statistic for prior-year assault homicides and those have been declining, so I'd expect fewer of those next year.

Anyway, I may well dig up some more statistics about murders, but let me end this post with a prediction: I predict that 2010 will have no more than 215 homicides. When you add in the prior-year assaults, I'll take 220 as an upper bound for the official homicide tally in 2010.

Summary graphs for the year:

Finally, for the big nerds out there, here's the summary of homicides resulting from prior year assaults:

2007 - 5 (1991, 1997, 2x 1999, 2005)
2008 - 6 (1985, 1995, 1996, 2000, 2006, 2007)
2009 - 14 (1988, 1994, 1997, 1998, 1999, 2002, 2003, 2005, 2006, 2007, 4x 2008)

Also, here's a link to my static XML murder charts.

The MARC Train System in Graphs

Recently I've started using the MARC train system a lot (precipitated by wrecking my car and needing to get to work). It's more expensive than driving and my commute is not bad (I have a reverse commute), but I've found it's really a pleasant way to get to and from work. I've also found that there are WAY more people riding the train that I'd thought. I stick to the Baltimore area, but I'm super impressed about how many people are using the trains every day.

The MTA does not publish ridership statistics on the MARC trains, so I emailed their “Contact Us” page. Much to my (pleasant) surprise, they replied almost immediately and were more than happy to share information. In a world where most places ignore your emails or take days to give you a non-answer, the MTA is a great exception. Anyway, I learned some interesting facts:

1. MARC train get a lot of riders
2. Generally, more people are riding the MARC now than ever before
3. It's impossible to make strong statements about how much ridership the MARC is getting

Statements #1 and #2 come from the data that the MTA supplied me. Statement #3 comes from their ridership counting methodology. Here is exactly how they determine daily ridership: on the first Wednesday of the month conductors count everyone who gets on and off at each station. Why Wednesday? Because Wednesday is typically the peak usage day for the system. So, as you'd expect, the data is SUPER noisy and absolute numbers are unreliable. However, after looking it over I'd say that it's probably pretty good from a general trends standpoint. Getting better data is probably possible, but very expensive and of questionable usefulness. I'm pretty sure that the data the MTA does get is good enough to manage the system.

On the other hand, what the MARC data lacks in detail on a day-to-day basis is made up for in it's historical value. The MTA sent me a spreadsheet with their data for monthly ridership counts going back to October 2001! They included their 12 month moving average data going back to February 2002! And, in the spirit of sharing, I've put that spreadsheet up for anyone to download.

It's a lot of data, and whenever I'm confronted with a lot of data I try to graph it to make some sort of sense of it all. So since they sent me this data I've been manipulating it in different ways, trying to see what I can learn and how best to describe the whole system.

(Note: The following discussion assumes that you have a passing knowledge of the MARC train system. Wikipedia and the MTA have plenty of information, but basically you should know that there are 3 passenger train lines – the Penn Line, the Camden Line, and the Brunswick Line. The Penn Line operates on the Amtrak-owned Northeast Corridor tracks, the Camden Line and Brunswick Line are at the mercy of CSX freight trains. All lines terminate at Washington Union Station. The Camden Line terminates at Camden Yards in Baltimore. The Penn Line passes through Baltimore Penn Station and continues towards Aberdeen and terminates at Perryville. The Brunswick Line has two spurs, one to Martinsburg, WV and the other to Frederick.)

A final note on this data. The MTA counts total station usage (i.e. boardings plus alightings), so the number of passengers is the total usage divided by 2. All of these numbers are daily numbers, but counted on peak usage days, so the average is discounted by some amount (which I won't even guess at). The MARC trains operate weekdays (an average of 250 days per year).

First off, total station usage by station. I have split Washington Union Station into 3 pieces, one for each of the rail lines.

First of all, you're probably thinking “Wow, I never knew that there were so many MARC stations!” and “Wow, everyone's going to DC and they're doing it on the Penn Line.” The Penn Line blows the Camden and Brunswick lines out of the water in terms of total ridership. In June 2009, the Penn Line accounted for 63.5% of total MARC system usage. There are many reasons for this, including facts like better on-time performance because the Penn Line is on Amtrak-owned tracks, good station locations in population centers, and the whole idea of the rich getting richer – the Penn Line is highly used so more capital investment is made on the Penn Line to length platforms, build parkings spaces, etc.

What does total system usage look like? Well, in June 2009 the 12 month moving average of total usage was running at 34,274, which indicates over 17,000 passengers on peak days. That's a lot of cars off the road when you think about. Especially considering that roads and traffic delays are fairly non-linear, the more cars on the road the worse the effect of each marginal car. Since most of these trains run for commuters to reach DC, traffic could be far worse without this service.

Just how many of these passengers are going to DC? From the data I have, I can't answer that question. I can, however, answer a related question, “How many of these passengers arrive or depart from Union Station?” And, “How has that changed over time?”

This chart shows some very interesting trends. Over the course of the last 7 years, the Brunswick Line has increased the proportion of trips that do not involve Union Station from 30% to 40%. That's very helpful for the keeping Union Station from being overwhelmed (spoiler alert: Union Station is pretty much overwhelmed by commuter traffic). I think it's pretty easy to explain this trend though. The Brunswick Line makes stops at Rockville, Kensington, and Silver Spring – good place to get off the MARC and get onto the Metro. Many of the commuters on the Brunswick Line may well be going to DC, they just have better options than Union Station.

The second interesting trends on that chart is that the Camden Line's fraction of travelers not going to Union Station peaked in 2008 and has since decreased. My estimation there would be that during high gas prices in 2008 a few more people started to use the Camden Line to commute to downtown Baltimore. Baltimore's traffic and parking situation is nothing like DC's, so when gas prices eased people reverted to their old ways. Honestly though, this could just be a strange blip in the data. The Penn Line has such noisy data for trips that do not involve Union Station that it's hard to understand. When you look at total trips (instead of a fraction of the whole), the data is noisy enough to make you think there is just something wrong with it.

There are some strange dips and peaks in the Penn Line data while the Camden Line and Brunswick Line show much smoother trends. What is good news for the MARC system is the combination of these two graphs. Trips that do not involve Union Station are increasing faster than overall system growth (as evidenced by the fact that total number of trips has increased as well as the fraction of the total). This means that instead of a system that runs trains full of DC commuters one-way and empty trains the other, you are starting to get a few more paying customers on those trains that would otherwise be empty.

Now for a look at the total system usage over the last few years:

If you're a fan of public transit you've got to love a chart that looks like that. The R2 value is 0.96 for a line of increasing ridership from 2002 through 2009. The fit line says every day from February 2002 to June 2009, an additional 1.75 passengers started riding MARC trains. That's great news for the system, but it's not unconditionally good news. I've had a hard time finding official numbers on what “capacity” actually is for the system, but the numbers I have seen are striking similar to actual usage. That means that system is actually operating near capacity and could probably increase ridership further with additional resources.

This is a lot of growth, but where is it coming from? Are there stations that have actually seen fewer riders? In general, growth is everywhere; in specific, the Penn Line. Over the past 5 years the Penn Line has added more usage than the Camden Line has total.

Line	12 Mon. Moving Avg. Ridership		Increase	Increase (%)	Average Annual Growth Rate
	June 2004	June 2009
Penn	16,273	21,762	5,489	33.73%	6.0%
Camden	4,255	4,768	513	12.05%	2.3%
Brunswick	6,765	7,744	979	14.47%	2.7%
Total	27,293	34,274	6,980	25.58%	4.7%

Here are a few charts that show a “then and now” look at the three lines over the last five years. I've maintained the same scale between charts to illustrate how the Penn Line dominates the MARC system. I do not include Union Station simply because it would ruin the scale of the chart.




And finally, just because I have the data and can plot it, here is a look at Penn Line station usage over the last 7 years and Union Station usage by the three MARC lines.




For the Penn Line data, the most impressive part of this data is that even after the financial crisis and the tremendous drop in gas prices, the Penn Line has not lost passengers. Perhaps these passengers are like me, they started riding the train by necessity and they kept riding it because it's just a lot less stressful than fighting traffic. Honestly, I think the number one thing constraining ridership at some of these stations is just parking availability. The plans to build additional parking at West Baltimore will likely increase the ridership there.

Meanwhile, the data on Union Station shows just why that train station is able to support so many businesses and shops while Baltimore's Penn Station can barely support a snack stand and a souvenir store. Actually, that is a bit of a unfair comparison, Penn Station seems to have more than enough traffic to support a few more commercial enterprises – but I'll have more thoughts on that in another blog post.

Updated Murder Charts

It's been a few months since I've updated my murder charts online, but you can see the latest charts (updated thru 7/19) on my XML chart webpage. As of 7/19, we are at 122 murders for 2009 versus 116 at this time last year. That sort of seems like a big deal (murders are up 5.2%!), but murders are so infrequent and noisy that I don't think it makes much difference. Between 7/19 and 7/31 there were 9 murders in 2008. It's easy to imagine fewer happening this year.

Overall, we're running at 233 murders for the last 12 months. I counted 229 murders in 2008, so basically we're seeing the exact same murder rate for the last 18 months or so. Not bad considering that 2008 was the best year in decades for Baltimore.

Anyway, here's one more chart to illustrate how noisy murder statistics are, even in a city with as many murders are Baltimore:

Please note: July 2009 is a partial total (as of 7/19)

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Notes: Again, I do not count people who die this year as a result of an act of violence in a prior year. Since I have the luxury of going back and editing my statistics (FBI, BPD, etc. do not), I am only counting violence in the year it occurs. For more of a discussion on why I do this, see my previous posts on murders from January 2009 and March 2009.

Baltimore Homicide Rate Update

Update (7/25/09): The data in this post is now fairly out of date. I think the discussion in this post is still relevant and worth reading, so I do recommend that you keep reading. If you're looking for the most recent data, check out here.

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As any resident of Baltimore City knows, there are a lot of murders in this town. I remember when I first discovered Murder Ink in the City Paper years ago and first tried to comprehend the tremendous number of murders in this city. Hundreds per year! And for every murder there are how many attempted murders / shootings each year? It's just plain madness.

I was excited as anyone as 2008 progressed and it started to look like Baltimore was having an out-of-trend year for murders. Despite a few very violent months (March, June, November and December were particularly bad last year), Baltimore ended 2008 with the lowest murder tally in two decades. Baltimore's per capita murder rate is still shockingly high as there are far fewer city residents today than 20 years ago, but last year was a marked departure from the rest of the decade (as I detailed in a post in January). In that post I noted that we shouldn't necessarily lose hope just because November and December had been pretty violent and January opened with 14 murders in 9 days.

Three months later I am happy to have been proven more or less correct. One of those 14 murders was determined to be justified as self-defense and the finally 22 days of January saw only 8 murders (not awesome, but not bad either). Since January I've been keeping track of murderous events and plotting them on some charts. A couple weeks ago I figured out how to make some nice Flash graphs of the data and put them up on a static website. In this post I publish some data as of 3/27/09, but the charts on my 2009 Baltimore Murder Charts site are updated approximately weekly.

According to my records, 228 murderous acts occurred in 2008. The official homicide tally was 234, but there were 6 people who died of injuries sustained in prior-year incidents. Since I'm interested in how deadly the city is right now, I don't track those numbers (although the FBI and others do). I have the opportunity to go back and edit my data, so if someone dies in 2009 from 2008 injuries, I'm going to back and count that on the date the incident occurred instead of the when the death occurred.

Anyway, the main reason I wanted to track murders this year was to be able to produce a "Trailing 12 Months Murders" chart. I think it's pretty informative and gives a good feel for whether or not murder rates have increased or not. For example, based on a very violent January, there is a perception that Baltimore is not going to be able to maintain last year's reduced murder rate. What I think has been under reported is that February 2009 had only 15 murders, the same number as February 2008.


As you can see from the Trailing 12 Months (TTM) Murders chart above, we're really not seeing any leap in violence this year. In fact, if you use a 30-day moving window to smooth out data a little, it's varied between 233.4 and 236.5. Above the 2008 total, but it certainly shows no sign of reverting to the bad old pre-2008 days of 250+ murders/year.

I think that it's important to consider some of these other graphs, just this week I heard a story on WYPR called "Murders Spike in Baltimore's Northeast District". They state that "Baltimore's homicide rate is nearly 25 percent higher then at this time last year." At the time of the story there were 47 murders in the city. Based on my records, at that time last year there were 40 or 41 murders (depending on exactly when the story was produced). By my count, that's (at most) 7/40 = 17.5% increase. Maybe I'm splitting hairs here, but I wouldn't exactly round 17.5% to 25%. I think I'd round it to either "nearly 20 percent" or "just over 15%". I guess the point of the story is that there have been more murders in the Northeastern District than normal. Still, I don't see why WYPR would want to talk up the homicide rate in Baltimore. They do note in the story that "Like other districts, the Northeast has seen a decline in robberies, burglaries and assaults from the same time last year."

So basically what the numbers show is that crime is down in Baltimore, except for some isolated, noisy statistics like murders in a certain district. Why not just be happy that murders are pretty much within the noise of last year's number - which was the lowest in two decades?? I guess I just don't understand WYPR's angle. 2009 is just not that much worse than 2008, especially if you take a look at these charts:

I look at the data I've got on murders this year and here's what I see:

• After a bump in early January, the murder rate has been lower than last year for 2.5 months. (We were +10 on 1/9/09 compared to +5 on 3/27/09)
• If you look at how many murders occurred in the 4th quarter of 2008 the 1st quarter of 2009 looks great.
• I think we'll briefly be even with last year on cumulative murders in the first couple days in April, but probably run above 2008 until at least June.
• I see no reason to believe we won't finish the year at more or less the same total as last year -> I think we may have seen Baltimore's homicide rate reset from the 250-270 range to something in the 220-240 range.

You know, it might be just about time to end completely doom and gloom picture of Baltimore's crime rate that has become true by definition. It's bad, it's a serious problem that requires enormous improvement, and it disproportionately affects the African-American community. But it has improved in recent years. We may have to start giving the Baltimore Police Department a little credit and the fact that the city is working better with Federal law enforcement probably helps. There are also a lot of community-based organizations that have contributed to the progress that has been made. We're clearly not there yet, but I don't think that we should continue to view crime in Baltimore as inevitable and uncontrollable.

I think we have to hope that economy does bottom out in 2009 and that unemployment peaks in early 2010 (as I've heard predicted) and does not take too long to recover. Baltimore's made a lot of progress in this decade, I'm looking forward to that continuing once we get to the other side of this recession. I feel that's still the one wild card in all of this; how quickly can investment and economic activity in Baltimore recover? Can we maintain momentum and making Baltimore a nicer, safer, and more inclusive city? If that doesn't happen, if community programs start going bankrupt and can't find support, things could definitely take a turn for the worse.

Update on 2009 Murder Charts

So my project for the day has to be teach myself how to create a chart that I can update frequently and lives on a static webpage. I just can't figure out how to make Blogger work with the cool Flash-based chart that I've worked out, so I've had to sign up for another website*.

I'll post more about this later, but for now I'm just going to publish the post and update later:
You want murder charts? I've got your murder charts!

*FYI - That web hosting service is so full of advertisements, I can barely stand it. I'll have to find a better solution eventually.

More Thoughts on Murder - With Graphs!

After my recent post on Baltimore's low (by Baltimore standards) murder total last year, a couple people commented that we should look at per capita murders rather than the annual total.  I think that there is some truth in those comments, but after fooling around with the data a little, I can also see how you would get a misleading story.

First off, a quick word on my data sources; all data for 2000-2007 is from the FBI's annual Crime in the United States (CIUS) publication.  The CIUS summarizes the Uniform Crime Reporting (UCR) program every year.  I'd never really looked at this before, but it's an amazing amount of information that's available to everyone.  I'm jumping the gun a little on 2008, so any numbers for 2008 are unofficial and the per capita numbers are especially suspect because the Census Bureau has not released 2008 population estimates (so I assumed no population change since 2007, which is obviously false for places like Baltimore and Detroit).  Finally, we need to remember that these are population estimates, not full Census data.  Also, I'm no trained demographer, so I'm not necessarily qualified to really analyze any of this - but I do love to make a good chart.

I chose to look as far back as 2000 because 1) that's when I moved to Baltimore and 2) after you look too far back you start wondering if you're really comparing apples to apples.  Anyway, here's a quick plot of where we've been as a city:

So you can look at graph and see that it's not immediately obvious that a reduction in murders from 261 in 2000 to 234 in 2008 might not actually reduce the per capita murder rate in Baltimore.  Before we get to per capita murders, I'd like to think a little bit more about the total murders in Baltimore.

In 2000, Baltimore was home to about 648,000 people.  At the same time East Newark, New Jersey was home to 2,377 people.  From 2000 to 2008, 2,377 people were murdered in Baltimore.  That's right, it took only 9 years for Baltimore's criminals to exterminate a population equivalent to a small New Jersey borough.  Yes, it seems silly that New Jersey have a mayor and six city council members to govern the 0.1 square miles of land and 0.04 square miles of water that comprises the borough of East Newark, but I'm sure Mayor Joseph R. Smith would be very disappointed to have his entire city wiped out. 

I'm making fun of New Jersey, sure, but the numbers really are mind-boggling.  Just trying to wrap your mind around the idea of a couple thousand murders is tough.  Here's another way to look at it: from 2000 to 2007, Baltimore's population is estimated to have declined from 647,955 to 624,237 - a decline of 23,718 residents.  Over that same time period, 2,143 people were murdered in Baltimore (i.e. the entire population of Vernon, AL).  Murders alone account for 9.0% of Baltimore's 2000-2007 population decline!

This ridiculously high murder rate is made even more tragic because of it's disproportionate effect on certain populations of Baltimore.  For example, in 2008 91% of homicide victims are African-American in a city that is only 64% African-American (source: Baltimore Sun).  It's just unbelievable; it works out to a per capita murder rate five times higher for African-Americans than everyone else in 2008!

Speaking of per capita murder rates, without further ado, here's the chart you've all been waiting for:

With the usual warnings about comparing crime statistics, I'm going to launch into what I think I've learned by looking at that chart.  First of all, Baltimore's murder rate has been fairly constant, even when adjusted for a falling population.  Over this time period we've looked a lot like Detroit, but I wouldn't be surprised to see that relationship loosen up over the next couple years.  Detroit looks to be in for a much rougher economic ride than we are (knock on wood).  It is interesting that both Baltimore and Detroit saw a big dip in murders this year (but St. Louis jumped out of trend).  St. Louis's trend line is a little scary because they saw a big one-year dip earlier this decade, but then jumped right back up to a murder rate in the high 30's.  Washington DC does give us a little hope, they managed to reset to a new, lower murder rate in the middle of this decade.

Other things you might want to know (but are not immediately obvious) - the city of St. Louis has about half Baltimore's population, so you'd expect the data to be a bit noisier since the murder rate LSB in St. Louis is twice as large as in Baltimore.  DC is approximately the same size at this point (because Baltimore has lost a lot of population and DC is fairly steady) and Detroit is larger.  However, I'd expect a big upward revision in Detroit's per capita murder rate because they are losing population fast enough that my "re-use the 2007 population estimate" makes the denominator too big.

Finally, it's kind of interesting how rock-steady the national murder rate has been this decade.  It's varied from 5.5 to 5.7 - which is actually way down from the mid-1980's (when it was over 8 for a few years).  When you look at the time-series data from the 1980's to the present you really start to appreciate the drop in violent crime nationwide.  This is probably why your parents worry so much about you living in the city.  Their concept of urban crime was set a generation ago, when it was objectively more dangerous to live anywhere!

As I said in my previous post, 2008 was a good year for Baltimore in terms of murders.  We were 3.28 sigma below the 2000-2007 average for total murders (although, due to the vagaries of population estimates and a falling population we were only 1.62 sigma lower than average for the per capita murder rate).  It'd sure be nice to say that 2008 was statistically significant and that something has really changed in Baltimore - that what the police are doing different is definitely working - but the first nine days of 2009 sure haven't helped (12 murders plus a shooting victim on life support).

The problem here is that for all the good work that the police may have done in 2008, 2-3 very violent months (November to now) could spell real trouble.  Many people have criticized the Baltimore Police for jumping from strategy to strategy.  If murders stay high for another 2 months, even if it's not necessarily out of trend for the last decade, there will be pressure on the police to change tactics yet again.  Those crime rate graphs are powerful tools but as the platitude goes, with great power comes great responsibility.  It is very, very easy to make a graph say whatever you'd like.

Working in a technical field, I see plots of things ALL the time.  Even though your natural instinct is to look a the pretty lines or bars or whatever, you have to train yourself to first look at the axes, at the units, at the title, and then ask whoever made the graph "Where did you get your data?"  Or "How did you calculate x?"  Contrary to popular belief, measured data is not the end-all, be-all of engineering.  Probably about half of all charts of measured data I see have some sort of fatal problem.  That's when you start to see who the really good engineers are.  The good engineers look a plot of data, even measured data, and if it doesn't match up to what their technical intuition says reality ought to look like they'll just say "I don't believe that, I think there's something wrong with the measurement."  So after arguing about it for half an hour, someone will agree to go back and remeasure.  A bad cal on the measurement equipment, a loose connector, operator misunderstood directions, measured from the wrong datum, measured the wrong channel, measured the wrong serial number, forgot to turn on the coolant, error in the test software, error in the spreadsheet math, test equipment not sensitive enough... the list of things that can go wrong in a measurement is endless.

So what does that have to do with anything?  My point is that we're measuring physical properties at my workplace.  I mean, these are things that are governed by physics, things that can't change.  The most important thing to remember in engineering is that those measurements aren't the truth, if you're lucky you get a picture of what the truth probably looks like.  So I figure that maybe half of all graphs of measured physical data are misleading or do not tell the whole truth (eventually you get there, but it takes a few iterations).  Now we're talking about something that is not governed by a physical, or even rational, process.  We're talking about violent crime and murder, so a short-term spike gets noticed.  Even if it were just truly random process, sometimes you get a clump, the human brain tries to see patterns in randomness.  But it's hard to adjust your mind to the idea that "Yeah, even if this were random, we could get 12 murders in 9 days," it's an emotional issue that skips over that logical part of your brain.  People see 12 murders in 9 days and think "Surely this is a trend!  This is a crisis!"  But it doesn't have to be.  It could just be a random coincidence.  Just looking at the graph doesn't tell you the story.

Finally, murders are not caused by a mechanistic, or even rational, process.  So to some extent, saying "We followed X police procedure and saw a Y% reduction in murders" is a worthless statement.  There's a correlation all right, but is there a causal relationship?  Murders are not one of those things that you can afford to have a control in your experiment (not that there are not advanced statistical methods that professionals can use to evaluate procedures that do a better job of controlling for other variables).  My advice would be to take a look at how other forms of crime change, because some crimes are more rational that others.  I may yet do this, but I'm also afraid that any improvements made by the Baltimore PD might be swamped out by the huge effect of the recession and increased unemployment.  

Overall, I sure hope that they give Bealefield a little while longer to apply his strategies before forcing him to change to something new.  I like a lot of the much-reported ideas (closer work with the state's attorney and US district attorney, sending repeat gun offenders away to federal prison for longer sentences, working harder to prevent domestic violence before it turns into assault/murder, focusing on arrest warrants for violent offenders) and would like to see how they turn out.

Ok, time for one last chart even though I've said about graphs and statistics are often misleading (every engineer can tell you about the time they passed some product because 4 out of 10 tested perfect only to find out later that 5 of the other 6 would have failed).  I mean, despite all their drawbacks, a good plot or graph can sure be interesting.

(On the plot above I am counting murderous acts that occur in that year, so if someone dies of injuries sustained in prior year violence they are not counted.  Since I have this all in a file now, if someone dies in 2009 from 2008 injuries, I will update my 2008 murder count instead of 2009 (this is the opposite of how Baltimore's PD (and I think the UCR) count murders)).

PS - I spent so much time on this post, I made a PDF version of it that is easier to read.