1. Measuring Delinquency
CRIM 302

2. Sources for Measuring Crime & Delinquency
Official Data=Archived data held by an institution or agency
Examples: Uniform Crime Reports, Juvenile Court Data
Self-Report Data=Information received from the subjects under study
Self-Reported Victimization: National Crime Victimization Survey
Self-Reported Delinquency: National Youth Survey

3. Ways of Measuring Crime & Delinquency
Raw Numbers: Simple count of individual events
Rates: Sum of Individual Events Compared to Population at Large
No. of Crimes * 100,000=# Crimes/100,000 in population
No. of People in Population
Allows for accurate comparison across groups, locations, etc.
Percent Change: Proportion of change in individual events from one time to another
T2-T1 * 100%= % Percent change from Time 1 to Time 2 T1

4. Computation Examples
5000 crimes committed in community of 500,000 people
(500/500,000) * 100,000
.001 *100,000
100 crimes/100,000 people
Or .001*1000=1 crime/1000 people
Crime in 2002=1000; crime in 2003=500
(( )/1000) *100%
(-500/1000)*100%
(-.5) *100%=50% decrease in crime

5. Interpreting the Numbers
Tyranny of small numbers
Small increase in small numbers results in large percentage increases
100 crimes
10 juveniles +7  Increase 70%
90 adults  +45  Increase 50%
Impact of crime and actual nature of the trend can be easily exaggerated

6. Other Misleading Uses of Data
Long-term trends v. short-term trend
Short-term increase may not be dramatic if viewed in the long-term
Comparisons
Using the lowest points as a base year for comparison
Not using a comparison group

7. Official Data: Uniform Crime Reports
The Federal Bureau of Investigation (FBI) began collecting data from law enforcement agencies on number of crimes reported to police in 1929
The UCR covers over 95% of the United States and reports:
No. of Crimes Reported to Police
No. & characteristics of Offenders Arrested
No. of Crimes Cleared by Police
Additional Information Provided about Homicide, Police Department Characteristics, Crime Consequences

8. Substance of the UCR
UCR represents one of two primary measures of crime trends for the U.S.
Index and Non-Index Crimes
Index Crimes Partitioned into 2 Parts
Violent Crimes: Murder/Manslaughter; Aggravated Assault; Robbery; Rape
Property Crimes: Burglary, Motor Vehicle Theft, Larceny, Arson

9. Strengths
Best measure of crime across the nation that we currently have
Validity for certain crimes
Problems tend to be stable over time, allowing trends and patterns to surface
Easy to access and inexpensive
Allows for city and regional trend comparisons
Provides detailed information on reporting patterns, who is arrested, and homicides

10. Weaknesses Doesn’t capture unreported crime--validity
Only most serious crime is reported
Does not include federal offenses
No. arrested is not equal to the actual number of youths who committed crime—group arrests overestimate juvenile crime
UCR is based on summary data that does not allow closer inspection into each arrest
Quality of data questionable:
Underreporting/overreporting by law enforcement
Variability of police practices/Use of arrest

11. Future of the UCR The National Incident-Based Reporting System
Launched by the FBI in 1988 for eventual replacement of the Uniform Crime Reports system
Collects a wide range of information on victims, offenders, and circumstances for more offenses than the UCR
Offenses tracked in NIBRS include violent crimes (e.g., homicide, assault, rape, robbery), property crimes (e.g., theft, arson, vandalism, fraud, embezzlement), and crimes against society (e.g., drug offenses, gambling, prostitution).
Collects information on multiple victims, multiple offenders, and multiple crimes that may be part of the same episode.
Not yet representative across the country—In 1997, 12 States were participating

12. Victimization
Two primary sources of data: National Crime Victimization Survey and the National Incident-Based Reporting System
The National Crime Victimization Survey (NCVS)
Victim self-report survey conducted by the U.S. Department of Commerce, Bureau of the Census on behalf of the U.S. Department of Justice, Bureau of Justice Statistics for the past 20 years
Data obtained from a nationally representative sample of roughly 43,000 households comprising nearly 100,000 persons
Remain in sample for 3 years
Interviewed every 6 months
All individuals 12 and older are interviewed about the frequency, characteristics and consequences of criminal victimizations they experienced within a particular time frame
Examines the following crimes: Rape, sexual assault, robbery, assault, theft, household burglary, and motor vehicle theft
Use data to compare with UCR trends as well as estimate the likelihood of victimization for the population and segments of the population (e.g., women, the elderly, members of various racial groups, city dwellers, or other groups)
Sources: Finkelhor, D. & Ormrod, R. (2000). Characteristics of Crimes Against Juveniles. Washington, DC: Department of Justice, Office of Juvenile Delinquency & Prevention; National Crime Victimization Survey; National Incident-Based Reporting System

13. Strengths of NCVS
Allows “check” of UCR (NCVS specific)—measures “dark figure of crime”
Collects a lot of information necessary to understand crime and victimization but not found in official crime reports
Not subject to political agendas (necessarily)

14. Weaknesses of NCVS & Self-Report
Lying
Exaggeration/Embarrassment
Memory and accurate time period
Cost and accessibility
Hidden Populations or missing populations
Inaccurate information
Administration of the Interview (face to face v. phone)
Refusal rates

15. Self-Report Data Monitoring the Future
Random sample of schools
12th graders in each selected school participate
Sub-sample is followed over time
National Youth Survey: Longitudinal, cohort study of juveniles throughout the teen-age years
Started 1976 with year olds who were followed until 1993 (27-33 years old)
Measured delinquency, victimization, and various theoretical variables
Provide much more information about the various relationships
The Youth Development Study
Recent effort to follow cohorts of youth in Richmond, VA, Denver, CO, and Rochester, NY
High-risk youth samples

16. Self-Report Differences
Contrary to arrest rates, there was no sharp increase in violence in self-report data, indicating arrest data may have exaggerated violent crime trend
Attention to the role of enforcement trends, discrimination, and paternalism
More youth commit crime than are arrested
Females commit crime at a rate more similar to males than seen in official statistics
The more delinquent a youth is, the greater the likelihood he/she will be victimized
Socioeconomic status is a better predictor of delinquency than race—the offending differential reduces substantially when SES is accounted for