All in one

Samuel Schiess

and 1 more

IntroductionIn the last years, humanity has crossed a major landmark with the increasing amount of the world population. In developed countries, > 70 % live in cities or urban areas \cite{Bettencourt2007}. With the increasing population, the humankind will be facing new challenges and existing problems can get worse. Not only problems of famine, water scarcity or energy need can occur, also socially problematic situations arise when many people live in the same spots \cite{Glaeser_1999}. The expectation of the population growth is steadily increasing, mostly in developing countries. On the other hand, in already developed countries the population increases in the urban areas with good connections to the economic centers. In this work, we will have a broader look at the expected population growth on a local level and its connection to the crime rate nowadays. Connected to the statement, that a large amount of people attract new immigrants \cite{Bettencourt2007} and the fact that crime should have a negative impact on the attractiveness of a region, this combination hides interesting insights. Our study area is formed by the city of Vernier with its 768 hectares and 35 300 inhabitants, situated in the Canton of Geneva and thus a part of the metropolitan area of the city of Geneva \cite{prsentation}.DataWe use population data from STATPOP of the year 2015 which is annually  surveyed by the Federal Statistical Office of Switzerland for the households of the country. Also, we use crime data from the police interventions in the area under study in the years from 2014 - 2017, coming from the event journals of the cantonal police of Geneva.MethodsFor the analysis of the region we created a grid of the region under study with the size of 100mx100m, which results in 403 cells in the populated area of Vernier. Our used input data is formed by the interventions of the police per cell and the expected percentual growth in this cell. Unfortunately, this allows us not to directly plot the dependency of those two variables and to calculate a regression, as the interventions are a discrete value. First, we need to assort the mean of the growth rate to their number of interventions, which leaves us with one mean growth rate per x interventions. In other words, the result includes the mean of the expected percentual growth in the cells with x interventions. As the computation and analysis of the interventions data and the number of foreigners already was processed in the former paper of \cite{geissler2017}, we were able to use the same algorithm for the representation of the police interventions.ResultsThe following chart shows the mean of the expected population growth until 2040 in percent, plotted over the number of police interventions in those regions. Also, two maps are displayed, that show a simple representation of the number of interventions and the expected growth rate.
Bild1

Samuel Schiess

and 1 more

Introduction The world human population is steadily increasing. In developed countries, > 70 % of the population live in cities or urban areas \cite{Bettencourt2007}. With the increase of the population, humankind is facing new challenges and existing problems become worse. Not only problems of famine, water scarcity or increased energy demand can occur, also socially problematic situations arise when many people live in the same spots \cite{Glaeser_1999}. With the density of humans living in the same area, also psychological problems occur. The social pressure rises and the concurrence in every domain is increasing, as so many people in the near areas specialize in the similar disciplines. On the other hand, people need to choose a lifestyle,  find their way of living and are responsible for their own well being. The pressure and responsibility can often end in psychological problems, which can lead to domestic violence, self-hatred and even suicide attempts. For actions that do not respect the law, the police is forced to intervene. In our digitized world everything and also those social interventions are recorded.Additionally, not only a growth of the population and the subsequent problems may be observed today. Also the mixing of the cultures and nationalities all over the world gets more important and brings new possibilities and advantages, but also new problems. In common speaking, the foreign cultures have often another treatment of psychological diseases, health, crime and violence than the native culture in for example Western Europe. This may be right in some cases, but the connection between social troubles and the percentage of foreigners in specific areas has never been clearly stated \cite{Entorf_2000}. In the case-study of the municipality of Vernier, we have access to data from the interventions due to social reasons and the demographic properties of the area under study. The context of those two variables is often taken as a political argument from right-wing parties, but a more narrow investigation will be provided in this paper. Our study area is formed by the city of Vernier with its 768 hectares and 35 300 inhabitants, situated in the Canton of Geneva and thus a part of the metropolitan area of the city of Geneva \cite{officiel}. The main focus will be set to investigate the spatial correlation between those two variables. In addition to that, other statistical measurements will be provided, based on the data set and the area given. HypothesisIn the first step we want to investigate the existence and the properties of hotspots in the region of Vernier regarding the two factors social interventions by the police and the origin of the population. Secondly, the relation between those two variables is of interest and their spatial correlation will be investigated. The expected facts are, that both parameters underlie a spatial distribution and hotspots exist and that the positions of the hotspots and thus the parameters are positively correlated to each other. Data We use population data from STATPOP of the year 2015 which is annually  surveyed by the Federal Statistical Office of Switzerland for the households of the country \cite{2017a}. From this data, quantitative information about the total population, the number of Swiss, non-Swiss and non-European inhabitants have been used. The second data set used is the data published by the cantonal police department of Geneva. The data set provides all police interventions due to social reasons in the area under study from 2014 to 2017 \cite{sitg}.  MethodsAll spatial and statistical analyses have been performed with the software Geoda \cite{projecta}. QGIS (Version 2.18.) \cite{project} has been used for the visualization.Having the two data sets described, we were able to perform a first statistical analysis. Therefore we performed the processing chain shown in Figure 1. The first step was to create a grid over the study area of vernier with a cell-size of 100 m x 100 m. For each cell, the total number of interventions has been summed up and divided by the total number of the population in this specific cell. Additionally, the number of Swiss, Non-Swiss, and Non-European inhabitants has been computed for each cell. To get the percentage of the different origins, those numbers have also been divided through the total number of the population within the cell. With the obtained variables, we were able to perform a first Linear Regression (Non-Swiss/Interventions, Non-European/Interventions). In addition to the Linear Regression, we also computed the Raw Rate. Therefore, the number of interventions divided by the total population was divided through the percentage of Non-Swiss and Non-European inhabitants within each cell.