Investigating Police Brutality in Los Angeles

Excessive use of force by law enforcement is by no means a novel phenomenon in the United States. However, with high-profile cases like Michael Brown, Eric Garner, and most recently Greg Gunn, fueling national movements such as #BlackLivesMatter, race-related incidences of police brutality are receiving worldwide media attention.

I investigated geographic trends in reported police brutality, using Los Angeles County at the census tract level and data from The Guardian’s project “The Counted,” a comprehensive dataset that records all people killed by police and other law enforcement agencies in the US, for the year 2015.

To measure the effect of location on incidences of police brutality, I conducted a hot spot analysis, which identifies statistically significant spatial clusters of high (hot spots) and low police brutality (cold spots). Essentially, the hot spots/cold spots indicate whether observed spatial clustering of police brutality events is more pronounced than if the values were randomly distributed. We specified the spatial relationship for the analysis as Contiguity Edges, meaning that census tracts that share a boundary or overlap with a census tract that contains a police brutality event will be weighted more that those that don’t in the analysis.

Below is a map depicting the results of the hot spot analysis.

policebrutalityla

The hot spots depicted in the map reveal the relationship between location and the occurrence of police brutality. The neighborhoods enveloped in hot spots are those with an abnormally high number of police brutality events, indicating that these areas may be disproportionately affected by excessive use of force by law enforcement.

Looking demographically at both the incidences themselves and these hot spot neighborhoods can shed some light on why these areas have abnormally high police brutality. Right off the bat, the number of blue and green dots (Hispanic/Latino and black victims, respectively), dominates the map. Breaking down by race, there were 30 victims of Hispanic/Latino descent, 11 black, 4 Asian/Pacific Islander, 7 white, and 1 Arab-American. In addition, most of the incidences with blacks as victims happen in LA neighborhoods that have a large population of blacks, such as Willowbrook and Westmont. The same trend also appears when focusing on Hispanic/Latino victims: most Hispanic/Latino victims died in neighborhoods with large populations of Hispanics/Latinos, such as Los Angeles proper and Eastern LA County (Baldwin Park, Irwindale, West Covina).

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Journalists and Maps: The Need for Teaching Quantitative Literacy to Everyone

 

In recent years programs like ArcGIS and Tableau have made it very easy to produce maps. Journalists have responded by richly illustrating their articles with quantitative data displayed as maps.  Maps are both attractive and easier to explore visually than the same data provided in tabular form, so in many ways they are ideal illustrations. For the average reader information transmitted as quantitative data appears authoritative and these maps are no exception.  On the surface they seem real and informative. Unfortunately, just as with any data-driven information maps can inadvertently be misleading.

In a recent example, NBC news illustrates an article about the Supreme Court consideration of a Texas law that would force the closure of a high percentage of existing abortion clinics across the country were similar laws to be enforced or enacted more broadly with a map of the U.S. showing the number of abortions per state in 2012, using data from the CDC (Center for Disease Control).

A quick perusal of this map seems to show why Texas is so concerned about abortions.  After all it is one of the states with the most abortions.  After a moment’s examination, the viewer might (or might not) note that the states with the highest populations also seem to have the largest numbers of abortions.

AbortionNumber

Thus, this map really tells us little about which states have the biggest problem with abortions.  Some kind of standardization by population is needed.  One option would be to just use population size. Since the number of women of women who might potentially become pregnant and secure an abortion (usually defined as the number of women between 15 and 44) does not necessarily vary by state in direct proportion to the population size, this statistic may be a better measure for standardization than simple population size.  In terms of the number of abortions per 1,000 women ages 15-44 Florida and New York have high rates of abortions, but Texas no longer looks unusual.

AbortionRate

But this still might not be the most revealing measure to use, since there is state to state variation in the birth rate.  In 2012 the average birth rate for the U.S. was 1.88, but Texas had a birth rate of 2.08.  The highest birth rate in the 50 states was 2.37 in Utah and the lowest 1.59 in Rhode Island. An option that takes into account the differential birth rates is to examine the ratio between the number of births and the number of abortions.  Using this measure, New York remains very high, but due to its relatively high birth rate Texas is even lower.

Abortion Ratio

The CDC provides all of these statistics, but the journalist chose the least revealing of the possible measures to display.  Journalists are generally both well-educated and, we assume, well-meaning.  Why not pick a better measure to map when it would have been equally easy to do so?  I suspect that the answer lies firmly in the laps of educators like myself.  While we prioritize skills like writing and speaking well, we do not mandate that all students graduate statistically or even quantitatively literate, but we should.

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Data Across the Curriculum: Using Geospatial Data to Illustrate Historical Change

History is a discipline that is founded on looking at changes over time, and for Sarah Purcell, Professor of History, data is an essential tool in measuring that change. More specifically, Purcell employs geospatial data to investigate historical change in both time and space for her Civil War & Reconstruction class, which focuses on the causes, progress, and consequences of the Civil War and Reconstruction with an emphasis on race, politics, economics, gender, and military conflict.

Purcell uses a stair-step approach in getting students exposed to geospatial data, first by using Google Maps to compare Civil War battleground locations to the locations of students’ hometowns, then investigating how other historians have used data, especially economic and demographic data, in tandem with historical narrative. Finally, Purcell has her students work with ArcGIS, an analytical map-making software, to visualize geographic trends in various historical data. For example, students in the class explore on black soldiers who enlisted in the U.S. Army during the Civil War in an in-class exercise (Figure 1) that encourages them to think critically about military data.

 

mapblacksoldiercotton1

 

To Sarah Purcell, data is important due to its wide applicability: using data in the context of history teaches a valuable lesson about how data can enhance just about any discipline. Moreover, in the history field, there exists a broad array of different types of data to be utilized, both qualitative and quantitative. While Purcell admits that some students have easier facility with working with data than others, she stresses that the struggle is important in internalizing quantitative literacy and getting accustomed to confronting data, an essential skill. The amount of involvement with data students get in her courses has impacted her students in a variety of ways: some students have gone on to get further training in ArcGIS via formal coursework, and others have been able to secure jobs, citing that employers are largely attracted to data skills in historical work.

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Mapping State Tax Expenditures to Demonstrate that All Else Really is Equal

Typically, when a business invests in a new piece of equipment, it cannot immediately deduct the full purchase price from its taxable income in the first year.  Instead, according to federal tax regulations, it deducts a percentage of the price in each of 2, 5, or 7 years depending on the type of equipment.  Businesses, of course, would prefer the tax deduction to happen in the first year so they have lower current taxes and therefore increased current cashflow which can be used to make additional investments that will pay off in the future.

In an effort to help small businesses, the federal government has long allowed for all investment costs below a specified threshold by any given firm to be immediately deducted.  This threshold, is specified in Section 179 of the tax code and is generally referred to as the Section 179 allowance.   For example, in 2002, all investment costs below $20,000 could be immediately deducted from taxable income but investment costs beyond $20,000 were subject to normal rules.

section179(2)

Since 2003, the government has worked to encourage business investment by significantly increased this threshold (see figure 1). Interestingly, as the government has increased the threshold, many states have made equivalent alterations to their state tax policies.  Other states have increased their Section 179 allowance some.  Still others have not increased Section 179 generosity at all.  In new research, I attempt to use this state-level variation in Section 179 generosity to estimate how manufacturing investment and employment respond to state Section 179 conformity.

An important step in this research process has been demonstrating that states that do and do not conform to the federal threshold are not substantially different in other ways that would affect investment or employment trends.  One major concern, in particular, is that conforming states might be concentrated in a single region.  If investment and employment is changing in this region for reasons other than Section 179 conformity, then the research design, which compares conforming and non-conforming states, would inappropriately attribute investment and employment effects to state 179 conformity when, in fact, these effects are really due to regional trends.

To allay this concern, I enlisted the help of Bonnie Brooks in DASIL to create an interactive ArcGIS application which shows the evolution of state 179 conformity during the years 2000 to 2011.  From the application, it is immediately apparent that state conformity or non-conformity is not concentrated in any region.  Thus, the ArcGIS application simply and elegantly allays concerns that regional trends may undermine the key assumption in this and all applied microeconometrics research project: that all else really is equal.

To use the map:

  • Drag the second ticker to the beginning of the timeline to start the visualization from the year 2000

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Mental Health Mortality, by Gender and Race

US President Barack Obama announced on January 5th that he would be taking executive action on gun control in light of a tragic trend of mass shootings in the last several years. Among the details of his gun control plan, he mentioned an increase in mental health services. While the expansion of mental health support may help in ameliorating the mass shootings epidemic, it may also has positive implications for reducing the number of Americans who die due to mental health causes. Using DASIL’s United States Mortality by Cause of Death, Race, and Gender visualization, one can see how deaths due to mental illness have been on the rise since the 1990s, and how the trend has had varying effects on every demographic:

mentalhealthmortagar

mentalhealthmortmvf

When looking at strictly male versus female deaths due to mental health causes, males in recent years are slightly more affected than females, at an average 3.84 deaths compared to 3.50 as of 2009. However, the 90s saw the reverse, with female fatalities at 1.92 compared to 1.37 in 1994.

mentalhealthmortmale

mentalhealthmortfem

When breaking down within each gender by race, a much different story emerges. For females, the sharp rise in deaths due to mental health is observed after the year 2000, which differs from the trend for all races and all genders. In addition, while each race follows the same sharp increase after the year 2000, white women are more adversely affected, at an average 5.92 deaths compared to 4.09 for blacks and 3.68 for other races in 2009. For males, on the other hand, the same sharp increase also appears after the year 2000, however the averages for each race are much less in comparison to their female counterparts. White males are also more adversely affected in comparison to other races, at 3.11 deaths, while black males are averaging 2.41 deaths and other races 2.33 deaths.

Why has mental health been more fatal for women across all demographics? One reason may be eating disorders. Women are more likely to contract an eating disorder than men (although that does not mean men do not develop eating disorders), and eating disorders have the highest mortality rate of any mental illness. For example, according to the South Carolina Department of Mental Health, the mortality rate associated with anorexia nervosa, one type of eating disorder, is 12 times higher than the death rate associated with all causes of death for females between the ages of 15-24 years old.

President Obama’s plan for enforced support and better resources for those suffering with mental illness will not only help in tackling the gun violence epidemic, but also larger instances of mental illness fatalities.

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