These models and simulations have been tagged “Justice”.
A Model of the Rate of Adult and Youth Crime and Community Spending in Bourke:
This is a model which displays whether community spending and the number of police can affect both adult and youth in committing a crime and becoming involved in community activities.
The Underlying Assumptions:
It is assumed that adults and youths in the town of Bourke are the populations that we are interested in modelling. It is noted that a high number of people in Bourke are engaged in crimes. Therefore, people in Bourke are tempted or likely to commit petty crimes. Since petty crimes are not serious offences, both adults and youths who commit petty crimes will return to being adults and youths. However, if the crime is thought to be serious, people are sent to jail as a consequence. Once the people in jail serve their jail sentence, they are released from jail and returned to being themselves.
In addition, the community introduced community activities, such as football clubs to reduce the number of crimes. Adults and youths in Bourke can be engaged with community activities and then return to being themselves.
The variables of community spending and number of police are sliders which demonstrate the level of influence on different stocks and relationships when the number of police and community spending are adjusted. The simulation will reflect the adjusted pattern/trend. For example, if we hold community spending constant while adjusting the number of police, we see at one police officer, many people are committing petty crimes and not many are caught and placed in jail. However, if we change the number of police to 30, we can see a decrease in petty crimes and an increase in going to jail. Furthermore, if we change police to 60, almost no one is committing a petty crime and no one is sent to jail.
• There are no other influences besides community spending and the number of police.
• The number of police is negatively related to the amount of petty crime.
• People are not learning from past mistakes.
• Community spending is negatively related to the amount of petty crime, but positively related to engaging in community activities.
• All values and time period, concepts are made up for the purposes of the model and for simplicity. They do not reflect real-life figures or time periods.
• Initial values are as follow:
Bourke youth: 1000
Bourke adult: 1000
Bourke petty crime: 500
Bourke jailed population: 500
Explanation of the model:
This model begins with adults and youths engaging in petty crime. Petty crime activities may include theft, assault or disorderly conduct like domestic violence in adults. Petty crime or the more serious crimes that lead to jail are affected by the number of police, and amount of community spending. The number of police affects the amount of people getting caught committing a petty crime or placed in jail. In addition, if people are not caught or did not commit a serious crime, they are returned to being adults and youths.
Moreover, for the people in jail, they are sentenced for a period of 4 months before being released back to being themselves. This period of 4 months can vary for different crimes and does not represent the actual or real-life time period for any crimes.
It is assumed that the justice reinvestment plan in Bourke will have community activities like football clubs. The purpose of the plan is to reduce the amount of crime and people going to jail. Thus, people in Bourke are engaged in these activities for 4 months, during which it prevents people from committing a crime.
About the model
depicts crime patterns among the youth population of Bourke, within varying
levels of policing expenditure, risk factor, rehabilitation expenditure and soccer
- The rehabilitation centre will tame
the most serious offenders, making them less likely to commit crime the next time round (Eg. Setting at 1.0)
- The soccer club will distract youths
from crime temptations, as well as nurture a sense of societal inclusion and wellbeing
in the long term (Eg. Setting at 0.4)
A stimulation on these parameters show that criminal rates are moderated, the ratio of youths in jail to town is lowered, and the outcome for the soccer club is very good with majority of participants feeling engaged.
statistics from the Australian Bureau of Statistics (ABS) show that Bourke
Shire Regional Council has approximately 3000 residents, made up of 65-63% adults
and 35-37% youths.
variable is in the denominator to create a hyperbolic trend. The aim was to achieve a
lower crime rate if police expenditure was increased, thus also a higher crime
rate if police expenditure was decreased. The figure in the numerator can be changed with the ‘maximum crime rate’ variable
which represents the asymptotic crime rate percentage. Where police = 100 the selected crime rate is
the formula incorporated the police as a variable, where the total amount of convicted crimes was subtracted from the total amount of crimes committed. However, the constant flow of crimes from repeat offender/a created an unrealistic fluctuation in the simulation. I
settled for a constant avoidance rate of 25%. This assumes that an adult or youth committing a crime for the first time is just as likely to
avoid conviction as a repeat offender.
is difficult to predict in a mathematical model how many adults or youths are convicted of crimes they commit. I
determined a reasonable guess of maximum 75% conviction rate when Police = 100. In this formula, decreasing police spending equates into
decreased conviction rate, which is considered a realistic representation.
is assumed that the average sentence for a youth is approximately 6 months
detention. For an adult, it will be assumed that the average sentence is 12
months gaol. The discrepancy is due to a few basic considerations that include
1. Adults are more often involved in serious crime which carries a longer
sentence 2. youths are convicted with shorter sentences for the same crime, in
the hopes that they will have a higher probability of full rehabilitation.
of adult/youth engagement was estimated to be a linear relation. The maximum rate of engagement, assuming expenditure = 100,
is set to 80%. This rate of engagement is a reasonable guess with consideration that there will also exist adults who refused to engage in the community and end up in
crime, and adults or youth that refuse to engage in the community or crime.
Expenditure variable is in the denominator to create a hyperbolic trend. The aim was to achieve a
lower boredom rate with a higher engagement expenditure, and thus a higher
boredom rate with a lower engagement expenditure. The figure in the numerator of 25 represents the asymptotic boredom rate percentage,
where if engagement expenditure = 100 the adult/youth boredom rate is maximised at 25%.
Justice Reinvestment in Bourke
A simple model of the township Bourke, showing the effects of community
engagement within the youth population.
This model uses the youth of Bourke and their temptation to commit crimes.
These crimes are usually committed out of boredom and generally include:
Breaking and entering, stealing, vandalism etc. The model depicts that the increase of police
presents means that will be an increase of youths caught and convicted whilst
also providing in the reduction in the temptation to commit a crime. Those
youths that are caught and convicted are sent to juvenile detention where they
undertake rehabilitation. Depending on this rehabilitation youths will either
be released back into the community where they may attend school or youth
activities or become bored again and re-commit or released back into a life of
crime pending unsuccessful rehabilitation.
Taking into consideration the Justice Reinvestment plan some of the
funds used to increase policing will be used instead to improve community development.
This has a knock on effect on crime as there will be better youth activities
running to keep youths engaged and free of boredom. This keeps youths out of
juvenile detention and also encourages them to go to school.
School attendance also has an effect on the temptation to commit a
crime, if a youth is attending school then they are less likely to be out and
about committing crimes. It was noted by Bourke High school Annual report 2012
that their attendance was a little over 60%.
Upon simulation there are a number of graphs that have been generated,
these include Crime & Detention, Crime vs School, Crime vs Youth
Activities, Town, Detention & Youth Engagement and School vs Youth
Activities. These graphs along with the variable sliders show what sort of
impact increase and decreasing the variable will have on the town and the youth’s
rate of crime and detention. These graphs can then be used to make a informed
decision on where it’s best to spend the money of the Justice Reinvestment
Things to note:
Youth in town: 1200.
Juvenile Detention: 100.
Violent families: 300
Detected violent families: 100.