Reference no: EM132922146

LEARNING OBJECTIVES

In this learning laboratory you will examine the stock, flow, feedback loop structure, and explore the dynamic behavior, of a system dynamics model of the heroin-related crime rate in a community. Your learning objectives are to gain some basic familiarity with the model, and use it to develop strategies for mitigating heroin-related crimes caused by successful law enforcement activities.

BACKGROUND INFORMATION

In a 1976 article that appeared in the Boston Globe, Saul Friedman reported that when the police are successful in seizing heroin from drug dealers, the result is an increase in the community's heroin-related crime rate. The reason this occurs is that the sudden reduction in heroin supply causes a shortage relative to a constant heroin demand (i.e., heroin addicts continue to require their daily fix). The short-run pressure of more heroin demand relative to heroin supply drives up the price of heroin from $7 per bag to $9 per bag. [It also incentivizes the drug suppliers to move heroin to the place at which they can receive a higher price.] Given that the heroin addicts are poor, in order to acquire the addition revenue necessary to pay the higher heroin price, the addicts commit more crimes (buglaries, robberies, etc.)

USER INTERACTION

The Heroin-Related Crime Rate Learning Laboratory is designed to allow the user to experiment with policies aimed at mitigating heroin-related crimes caused by successful law enforcement activities. The user can fight the problem on the demand side by funneling resources to addicts in an effort to get them to quit using heroin, or never start using the drug in the first place, or on the supply side by funneling resources to the law enforcement community in an effort to help them get more drugs off the street. The user can also specify the economic conditions of the community within which the problem is occurring to see if resources are better allocated to this area.

SCORING METRIC

In the Heroin-Related Crime Rate Learning Laboratory simulation runs are evaluated with a simple metric: the total number of heroin-related crimes committed during the simulation experiment. The lower the number of crimes, the better the score.

EXAMINING MODEL STRUCTURE

System dynamicists believe that a system's structure is responsible for its behavior. To begin using the learning laboratory click on either the "Examine Model Structure" button or the "Explore Model Behavior" button. Although you can easily move between the two areas, it's usually best to start by examining the system's STRUCTURE.

EXPLORING MODEL BEHAVIOR

When you are ready to begin exploring the model's BEHAVIOR go to the Simulation Set-Up dashboard by clicking on the "Explore Model Behavior" button. The base run should be set-up with all of the switches turned off, the fraction of the dealer's heroin supply seized on each raid set to 50%, the fraction of the addict's habit supported by crime set to 75%, and the revenue per crime set to $50. The latter two assumptions are set to mimic a poor community.

Once you have verified that the conditions are correct for the base run, click on the "Go Run the Simulation" button and examine the simulation dashboard. Be sure to clear any previous simulation runs that might be present by hitting the "Clear All Results" button.

1. To see the base run, hit the "Run the Model Once" button. What happens? Can you talk your way through the simulation run? What was the simulation score? Did the run mimic the reference mode?

Be sure to use the Set Run Name After Simulation button to specify a name for the run so that you can compare and contrast each simulation experiment.

Copy and paste a screen shot of the three graphs from the simulation dashboard into your homework document and add the appropriate commentary.

2. In the base run, law enforcement only raids the dealers one time. Turn on the multiple seizure rate policy and re-simulate. What happens now? Why? Be sure to name this simulation run so that you can compare it to other experiments.

Copy and paste a screen shot of the three graphs from the simulation dashboard into your homework document and add the appropriate commentary.

3. Try both the single and multiple seizure policies with both higher and lower values for the Fraction of Heroin Supply Seized parameter. What happens now? Do things get better when the police are more efficient in getting drugs off the street? Why?

Be sure to name thee simulation runs so that they can be compared to other experiments.

Copy and paste screen shots of the three graphs from the various simulation experiments into your homework document and add the appropriate commentary.

4. Try fighting the problem on the demand side by activating, one-by-one, the following policies:

(a) Slow Growth Policy. This policy examines the consequences of allocating resources toward preventing people from ever starting to use heroin.

(b) Addict Treatment Policy. This policy examines the consequences of allocating resources toward getting addicts into treatment programs, during which time they do not use heroin.

(c) Addict Recidivism Policy. This policy examines the consequences of allocating resources toward stopping addicts who are in treatment from slipping back into heroin use.

(d) Addict Quite Policy. This policy examines the consequences of allocating resources toward getting addicts who are in treatment to quite using heroin completely.

Which of these demand side policies is most effective? How do they relate to the supply side policies?

As before, be sure to name your simulation runs so that they can be compared to other experiments.

Copy and paste screen shots of the three graphs from the various simulation experiments into your homework document and add the appropriate commentary.

5. Try repeating several of the previous simulation experiments with the following pairs of economic conditions.

(a) Richer addicts and richer crime victims

(b) Poorer addicts and poorer crime victims

(c) Poorer addicts and richer crime victims

(d) Richer addicts and poorer crime victims.

What can you say about the impacts on the problem from the relative economic conditions of the community?

Again, be sure to name your simulation runs so that they can be compared to other experiments.

Copy and paste screen shots of the three graphs from the various simulation experiments into your homework document and add the appropriate commentary.

6. What are your overall conclusions vis-a-vis solving, or at least mitigating the problem? What would you tell the mayor of the community to do? The police chief? The person running the methadone clinic?

7. What are the flaws in the model? Can you think of any improvements?

Attachment:- HW.rar