INSIDE-OUT ECONOMICS / NORWICH CASE FILE01 / 03 · THE POLL
YOUR CITY. YOUR CHOICE.
THE NORWICH PURGE.
24 hours without criminal law. Which temptation would be hardest to resist?
Enter one vote per student from your Genially poll.
INSIDE-OUT ECONOMICS / NORWICH CASE FILE02 / 03 · TWO SHOCKS
TWO SHOCKS. ONE CITY.
01
THE POLICING SHOCKFewer police → greater opportunity to offend
HOW MUCH POLICING IS LEFT?100%
0% · NONE100% · NORMAL
02
THE SOCIAL REACTIONHow do people react when others start breaking the rules?
RESTRAINT: Even without police, conscience, reputation and retaliation still discourage crime.STARTING SCENARIO
WHAT HAPPENS TO RECORDED CRIME?Norwich city · Sep 2025–Aug 2026 | Murder: Norfolk · year to Mar 2026
INSIDE-OUT ECONOMICS / NORWICH CASE FILE03 / 03 · THE REVEAL
THE ECONOMIC SURPRISE
CRIME HAS A PRICE.
But which matters more: the chance of getting caught or the punishment?
01 · CHANCE OF BEING CAUGHT
1%
0% · NEVER100% · CERTAIN
02 · SIZE OF THE PENALTY
£10,000
£0£20,000
THE EXPECTED PENALTY
£100
Chance × punishment
A calculation, not a prediction of what a person will do.
TRY TWO SYSTEMS:A huge penalty can carry a surprisingly small expected cost.
THE TWIST: A smaller punishment can create a larger expected cost when getting caught is more likely.
Could even murder respond to its price?
Illustrative financial penalties; murder cannot be reduced to a monetary fine.
WHERE DO THE NUMBERS COME FROM?
Recorded baselines: Norwich shoplifting 2,434, burglary 406, robbery 186 (September 2025–August 2026). Murder: Norfolk county, 4 recorded offences (year ending March 2026). This is a different area and period, used only as a separate benchmark. Do not add it to Norwich city totals.
Policing effect: We use published US police-number elasticities: −0.17 for aggregate property crime (shoplifting proxy), −0.23 for burglary, −0.56 for robbery, and −0.67 for murder. Calculation: baseline × (policing remaining / 100)elasticity. Applying US estimates to Norwich is illustrative, not a local causal estimate.
At very low policing: The equation cannot be evaluated at zero, so it is capped at an effective 10% policing level. The 0–60% portion is a particularly uncertain extrapolation. No study predicts a legal 24-hour Purge.
Behavioural effect: Experimental research shows that visible rule-breaking can change other people's willingness to break rules (Gino, Ayal & Ariely, 2009). It does not measure how many extra murders result. We therefore test three clearly labelled assumed mechanisms: Restraint (no extra social amplification), Contagion (moderate amplification), Breakdown (stronger imitation, retaliation and escalation).
Student poll: The vote shares are mapped to each crime using an illustrative motivation matrix. Money favours acquisitive crime; Power and Payback favour confrontation; Thrill favours risky behaviour. A vote is not an admission of offending. The poll changes only the assumed behavioural addition, never the published police elasticity.
Equation: Scenario count = recorded baseline × policing factor × [1 + behavioural intensity × motive weight × policing-loss fraction]. The behavioural intensity is 0 (Restraint), 0.35 (Contagion), or 1.20 (Breakdown). Breakdown is a larger assumed amplification, not a measured homicide escalation rate. These are transparent sensitivity parameters, not experimental estimates.