1. Evaluating Theories of Crime

2. What is a “Theory?”
A statement of set of statements about the relationships between 2 or more events
In criminology?
Theories of crime
Theories of how the criminal justice system operates
A theory predicts what will happen, not how the world should be

3. How do you know a “good theory” when you see one?
Akers’ 6 criteria for evaluating a theory
1. Logical Consistency
2. Scope
3. Parsimony
4. Testability
5. Fit with Empirical Evidence
6. Usefulness of Policy Implications

4. Logical Consistency Clearly Defined Concepts
Concept = symbol/label that we apply to an abstract image
Examples?
Concepts must fit in a logical manner
BAD LOGIC: All crime is caused by imprisonment

5. SCOPE (not the mouthwash)
DEPENDENT variable
How “general” is your explanation?
Specific forms of crime/deviance?
All crime?
All crime, deviance, sin, and recklessness?
All else being equal, “Wider is Better”

6. Parsimony INDEPENDENT (predictor) variables
How complex is your explanation?
Parsimony: Low self-control is single cause of crime
Not: Crime caused by a combination of poverty, inequality, average daily temperature, intelligence, hair color, weight, daily stress…
All else being equal, more parsimony is better!

7. Testability A valid theory can be falsified Non-falsifiable theories?
Tautological arguments (crime causes crime)
Vague and open-ended statements (Freud)
Must be observe/measure concepts (little green men)

8. Is the theory correct? Survive empirical scrutiny
Few theories are entirely correct or false
To what degree is the theory supported?
Preponderance of evidence support?
Incorrect theories must be modified or discarded

9. Policy Implication
All crime theories attempt to identify the “causes” of crime.
Can the causes be reversed?
Does the theory translate into practice?
Example: Marxist theory of crime

10. Flow Chart for Evaluation
NO = Useless, stop here
Evaluate the
Following:
Scope
Parsimony
Policy Implications
Falsifiable?
Logical?
Yes
Empirical
Evidence?
YES
NO: Modify/Discard

11. Correlation and Causation
For Social Sciences (“Probabilistic”):
X (the “cause”) must precede Y (the “effect”)
X must be related to Y
The correlation cannot be spurious

12. Ruling out Spuriousness
Most commonly is the use of “Statistical Control”
Observe/measure factors that might render relationship spurious
Include these factors as “control variables” in a statistical model
Problems with this?

13. Methods for Studying Crime
Experiments
Survey Research
Cross-sectional
Longitudinal

14. Experiments Experimental Control is better that statistical control
“True Experiment”
Random Assignment
In criminology?
Typically “quasi” experiments
Rehabilitation based on theory
Manipulate criminal justice system

15. Survey Research Typically cross-sectional Recent trend = longitudinal
Usually high school students
Recent trend = longitudinal
Establish cause-effect ordering
Stability of criminal offending