each question must be a paragraph
Microsoft Word - CJBS 250 MIDTERM EXAM .docx 1 CJBS 250 – RESEARCH METHODS AND STATISTICS FOR CRIMINAL JUSTICE MIDTERM EXAM Exam Instructions This an open book exam but you are not permitted to collaborate with any other students on this exam. You will be required to read and review the assigned research article Titled " Using Terror Alert Levels to Estimate the Effect of Police on Crime.pdf, from the reading, you will answer exam questions about the research methodology used in the article. You should provide answers to the exam questions that incorporate concepts and material from textbook readings, and/or other course context material. Please read your assigned article carefully to ensure your success on the exam. The exam will consist of twenty-five essay questions and you will be given two hours to complete it. The exam questions will be released before the exam tonight Wednesday October 28, 2020 by 11:59pm so that you have time to adequately prepare your answers to the exam questions. The exam will be released on Blackboard Friday October 30, 2020 by 11:59pm, and the exam is due Wednesday November 4, 2020. Again, once you begin the exam you have two hours to complete it, you will not be able to exit the exam and then re-enter the exam. Once the time period allotted for the exam ends the exam will close whether you complete the exam in entirety or not. I will not accept any late submissions or submissions outside of Blackboard. Exam Questions 1. Whatexactlyisthepurposeofthestudy? 2. Whyisitworthstudying? 3. Doesthestudycontributetoourgeneralunderstandingofcrimeorpolicyresponses tocrime? 4. Doesithavepracticalsignificance? 5. Aswediscussedinthetextforthisclass,researchbeginsbyreviewingwhatothers havesaidaboutthetopic.Fromthisstudy’sliteraturereview,whatdowealready knowaboutthisresearchtopic? 6. Whatdon’tweknowfrompriorresearchorwhatisthegapinexistingknowledge? 7. Inthisstudy,isthisliteraturereviewadequate,whyorwhynot? 8. Whatspecificquestionsdidtheresearchtrytoanswer? 2 9. Givenwhatothershavefound,asstatedintheliteraturereview,whatnew informationdotheresearchersexpecttofind? 10. Whatistheindependentanddependentvariable(s)? 11. Whatconceptualdefinitionisusedinthisstudy? 12. Whomorwhatwilltheresearchersstudyinordertocollectdata? 13. Identifythesubjectsingeneraltermsandtheunitofanalysis. 14. Isitappropriatefortheresearcherstoselectasample?Ifso,howwillthe researchersdothat? 15. Ifthereisanypossibilitythattheresearchwillhaveanimpactonthosestudied, howwouldtheresearchersensurethattheyarenotharmedbytheresearch. 16. Howdotheresearchersoperationalizethekeyconceptstheywanttostudy? 17. Whatarethekeyvariablesinthestudy? 18. Howwilltheresearchersdefineandmeasurethem? 19. Dotheirdefinitionsandmeasurementmethodsduplicateordifferfromthoseof previousresearchonthistopic? 20. Howwilltheresearcherscollectthedatafortheirstudy(ordescribethedatasets theresearchersuseintheiranalysis? 21. Willtheyobservebehaviordirectlyorconductasurvey? 22. Willtheresearchesundertakefieldresearch,orwilltheyfocusonthereanalysisof dataalreadycollectedbyothers? 23. Whatlimitationsofthestudydotheresearchersdiscuss? 24. Canyouidentifyanyotherthreatstointernalorexternalvalidity?Ifso,whatare they? 25. Intwoparagraphs,giveyouroverallopinionoftheresearchmethodologyusedand thefindingsofthisstudy. Using Terror Alert Levels to Estimate the Effect of Police on Crime The University of Chicago The Booth School of Business of the University of Chicago The University of Chicago Law School Using Terror Alert Levels to Estimate the Effect of Police on Crime Author(s): By Jonathan Klick and Alexander Tabarrok Source: Journal of Law and Economics, Vol. 48, No. 1 (April 2005), pp. 267-279 Published by: The University of Chicago Press for The Booth School of Business of the University of Chicago and The University of Chicago Law School Stable URL: http://www.jstor.org/stable/10.1086/426877 . Accessed: 26/03/2015 11:05 Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at . http://www.jstor.org/page/info/about/policies/terms.jsp . JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact
[email protected]. . The University of Chicago Press, The University of Chicago, The Booth School of Business of the University of Chicago, The University of Chicago Law School are collaborating with JSTOR to digitize, preserve and extend access to Journal of Law and Economics. http://www.jstor.org This content downloaded from 165.123.19.211 on Thu, 26 Mar 2015 11:05:28 AM All use subject to JSTOR Terms and Conditions http://www.jstor.org/action/showPublisher?publisherCode=ucpress http://www.jstor.org/action/showPublisher?publisherCode=chicagobooth http://www.jstor.org/action/showPublisher?publisherCode=chicagobooth http://www.jstor.org/action/showPublisher?publisherCode=chicagolaw http://www.jstor.org/stable/10.1086/426877?origin=JSTOR-pdf http://www.jstor.org/page/info/about/policies/terms.jsp http://www.jstor.org/page/info/about/policies/terms.jsp 267 [Journal of Law and Economics, vol. XLVIII (April 2005)] � 2005 by The University of Chicago. All rights reserved. 0022-2186/2005/4801-0011$01.50 USING TERROR ALERT LEVELS TO ESTIMATE THE EFFECT OF POLICE ON CRIME* JONATHAN KLICK Florida State University and ALEXANDER TABARROK George Mason University Abstract Changes in the terror alert level set by the Department of Homeland Security provide a shock to police presence in Washington, D.C. Using daily crime data during the period the terror alert system has been in place, we show that the level of crime decreases significantly, both statistically and economically, during high-alert periods. The decrease in the level of crime is especially large in the National Mall. This provides strong evidence of the causal effect of police on the level of crime and suggests a research strategy that can be used in other cities. I. Introduction Do police deter crime? A majority of studies surveyed found that either there is no relationship or increases in the number of police are associated with increases in the level of crime.1 Most economists are suspicious of these results. It is no surprise to find that places with an inordinate amount of crime tend to employ a large police force. Nor is it unreasonable to suspect that jurisdictions increase the size of their police forces when they witness or expect an increase in the level of crime. Thus, neither cross-sectional nor time-series analyses can credibly identify a causal effect of police on crime. But crime and crime fighting cost Americans hundreds of billion of dollars every year. Expenditures on police alone, for example, are over $65 billion a year.2 The enormous expenditure on policing makes breaking the endo- geneity circle more than a mere academic puzzle. Isolating a causal rela- * The authors thank Bill Evans, Eric Helland, Ted Joyce, Steven Levitt, and Thomas Strat- mann for helpful comments. We thank Anil Caliskan for excellent research assistance. 1 For the survey, see Samuel Cameron, The Economics of Crime Deterrence: A Survey of Theory and Evidence, 41 Kyklos 301, 323 (1988). 2 See Sidra Lea Gifford, Justice Expenditure and Employment in the United States, 1999 (Bur. Just. Stat. Bull. No. NCJ 191746, February 2002) (http://www.ojp.usdoj.gov/bjs/pub/pdf/ jeeus99.pdf). This content downloaded from 165.123.19.211 on Thu, 26 Mar 2015 11:05:28 AM All use subject to JSTOR Terms and Conditions http://www.jstor.org/page/info/about/policies/terms.jsp 268 the journal of law and economics tionship between increases in the number of police and reductions in the level of crime has large policy consequences.3 II. Terror Alerts as Shocks to Police Presence In a seminal paper, Steven Levitt showed how the circle could be broken by identifying variations in police presence that were not caused by variations in crime.4 He found that police presence increased in mayoral and guber- natorial election years but not in off-election years. Since crime is unlikely to be correlated with election timing, this identification strategy can, in prin- ciple, break the circle. However, this strategy proved to be problematic in practice. Variations in police presence brought on by electoral cycles are not large, and variations in other factors impede precise estimation. Although Levitt initially did estimate a significant deterrent effect, Justin McCrary later showed that a programming error made Levitt’s results appear more precise than justified. McCrary concluded, “In the absence of stronger research de- signs, or perhaps heroic data collection, a precise estimate of the causal effect of police on crime will remain at large.”5 We claim that a stronger research design than that used in the past and a new data source let us better estimate the causal effect of police on crime. On March 11, 2002, the Office of Homeland Security introduced the Home- land Security Advisory System (HSAS) to inform the public and other gov- ernment agencies about the risk of terrorist attacks. During high-alert times, the police increase their presence on the streets of Washington, D.C. We use the high-alert periods to break the circle of endogeneity to estimate the effect of police on crime. In addition to a stronger research design than that used in the past, we also improve on the data. Most previous studies use annual data. Annual data are subject to an inherent trade-off—a longer time series improves the precision of estimates but increases the possibility of omitted-variable bias. 3 It is interesting to note that combining police ($65 billion), judicial ($35 billion), and correction expenditures ($49 billion) gives a total direct spending on criminal justice of $149 billion—more than a third of that spent on elementary and secondary schooling ($433 billion as of 2001). Yet there are many more papers on the return to education than on the return to policing. 4 Steven D. Levitt, Using Electoral Cycles in Police Hiring to Estimate the Effect of Police on Crime, 87 Am. Econ. Rev. 270 (1997). For other notable attempts to break the endogeneity circle, see Thomas Marvell & Carlisle Moody, Police Levels, Crime Rates, and Specification Problems, 34 Criminology 609 (1996); Hope Corman & H. Naci Mocan, A Time-Series Analy- sis of Crime, Deterrence, and Drug Abuse in New York City, 90 Am. Econ. Rev. 584 (2000); and Steven D. Levitt, Using Electoral Cycles in Police Hiring to Estimate the Effects of Police on Crime: Reply, 92 Am. Econ. Rev. 1244 (2002). 5 Levitt, Reply, supra note 4, concedes the errors identified in Justin McCrary, Using Electoral Cycles in Police Hiring to Estimate the Effect of Police on Crime: Comment, 92 Am. Econ. Rev. 1236, 1242 (2002). However, Levitt’s study provides estimates using the number of municipal workers and firefighters as instruments to show that there is a statistically significant negative effect of police on crime. This content downloaded from 165.123.19.211 on Thu, 26 Mar 2015 11:05:28 AM All use subject to JSTOR Terms and Conditions http://www.jstor.org/page/info/about/policies/terms.jsp effect of police on crime 269 Panel data reduce the need for a long time series but raise the problem of endogeneity and omitted-variable bias in the cross-sectional component.6 We use daily crime data from a single city, Washington, D.C., for our analysis. Daily data are less subject to endogeneity problems from crime to police. Also, our focus on a single city reduces omitted-variable bias in the cross- sectional component. Our paper is most closely related to that by Rafael Di Tella and Ernesto Schargrodsky.7 A terrorist attack on the main Jewish center in Buenos Aires in July 1994 led to increased police presence on blocks with Jewish and Muslim institutions (mosques, synagogues, schools, and so forth). Di Tella and Schargrodsky found that auto theft declined by 75 percent on protected blocks but that little or no changes were observed one or two blocks distant. Like them, we take advantage of presumably exogenous shocks to police presence and the fact that these shocks may have different impacts across space and time. Our research design differs in two important respects, how- ever. First