Proiect statistică

Introduction

Measuring the development of crime in the world is a difficult task, due to the different ways of collecting the informations in each country. However the political and social importance of crime, together with public concern about the phenomenon, has made it increasingly important to try to obtain an overview of the situation in the world.

There are some indicators that are known they influence the increase in the number of criminal acts such as drugs and alcohol consumption, the high degree of poverty, the level of education, the age of population, the number of crimes that are reported to the police and others.

In this project I will analyse some possible factors with an impact in the total number of crimes recorded by the police during th year 2007 in 45 different countries countries in the world including a big part of Europe and some big developed countries in the world, such as the United States, Japan, New Zealand, Australia, South Africa and Canada.

Figure no.1 : The number of total crimes by country, based on Eurostat data Source: eurostat.ec.europa.eu.

From the graph above, we can observe that the number of total crimes recorded is higher in the countries that have a higher population. This is why the first factor analysed is the number of total population reported by each country in the year 2007.

The second factor taken into consideration is the yearly average of unemployment rate expressed in percentages for each country in 2007. Usually, when the unemployment rate is high, it means that there is a great number of people in that country without a job, which leads to low incomes for them. In such situations, people belive that they don’t have many options and they do things that they wouldn’t do under better circumstances.

On the other side, a higher number of police officers influences in a negative way the development of criminal acts in a country. The higher the number of policemens, the smaller the number of total crimes recorded in that country.

Finally, another factor that is considered to have impact in the increased number of criminality is the number of immigrants. Usually the people migrate due to their low level in the standard of living in their countries. This is why in their host country arrive a high number of poor immigrants which leads to the increase in the number of criminal acts in that country due to poverty.

The data used in this paper are recorded from EUROSTAT and the reference year is 2007

Table no 1: The analysed variables of the model

Country Total crimes(000) total population(000) unemployment rate(%) police officers(000) no of immigrants(000)

Belgium 1003 10585 7.5 38 146

Bulgaria 135 7679 6.9 18 2

Czech Republic 357 10287 5.3 44 104

Denmark 445 5447 3.8 11 65

Germany 6285 82315 8.4 250 681

Estonia 50 1342 4.7 3 4

Ireland 103 4313 4.6 13 89

Greece 423 11172 8.3 51 133

Spain 2310 44475 8.3 215 958

France 2197 63623 8.4 124 182

Italy 2933 59131 6.1 107 557

Cyprus 8 779 4 5 19

Latvia 56 2281 6 8 4

Lithuania 68 3385 4.3 11 9

Luxembourg 28 476 4.2 2 17

Hungary 427 10066 7.4 26 24

Malta 15 408 6.4 12 7

Netherlands 1214 16358 3.2 36 117

Austria 594 8283 4.4 27 107

Poland 1153 38125 9.6 98 15

Portugal 400 10599 8.1 52 46

Romania 281 2156 6.4 45 10

Slovenia 88 2010 4.9 8 29

Slovakia 111 5394 11.1 14 16

Finland 344 5277 6.9 8 26

Sweden 1306 9113 6.2 18 99

United Kingdom 494 60817 5.3 22 527

Croatia 76 4441 9.6 20 15

Turkey 963 69689 8.5 330 179

Norway 272 4681 2.5 7 62

Switzerland 326 7509 2.8 17 166

Albania 59 3157 13.8 12 83

United States 11252 301139 4.6 700 38356

Japan 2051 127433 3.9 46 2049

New Zealand 426 4115 3.6 8 642

Australia 831 20434 4.4 47 4097

South Africa 2639 43997 24.3 133 1107

Russian Federation 3555 142220 5.9 1779 12081

Canada 2303 33390 6 64 6107

Montenegro 9 624 14.7 5 69

Serbia 105 7397 18.8 20 458

Ukraine 1975 46465 2.7 176 6834

Liechtenstein 1 35 1.3 0.09 0.09

Iceland 13 307 1 0.6 8

Macedonia 26 2041 34.9 10 1

Source: eurostat.ec.europa.eu.

Regression analysis

From the econometric point of view, in order to prove the relationship between the number of total crimes and the total population, the unemployment rate, the number of police officers and number of immigrants, I will use the multiple linear regression analysis, a model which assumes a linear relationship between a dependent variable given by the number of total crimes, and a set of explanatory variables, the total population(000), the unemployment rate(%), the number of police officers(000) and number of immigrants(000), also called independent variables. The relationship between the dependent variable and the independent ones is given by the function:

Y = ß0 + ß1 X1 + ß2 X2 + ß3X3 + ß4X4+ e

Where: Y=number of total crimes(000)

X1=number of total population(000)

X2=unemployment rate(%)

X3=number of police officers(000)

X4=number of immigrants(000)

In this case, each of the slope coefficients, meaning ß1, ß2, ß3, ß4 are the partial derivatives of Y with respect to the X variable which they multiply. In order to calculate this coefficients, we have to solve the system given by these derivatives:

In this way, we obtain the regression model expressed by the function:

Y = 107.97 + 0.02 X1 + 12.80 X2 – 0.62X3 + 0.06X4

Interpretation of the coefficients

The intercept b0=107.97 predicts the number of total crimes in a country when all the explanatory variables are equal to zero. In this case, the intercept doesn’t have an interpretation.

Regarding the relationship between the total number of crimes and the population of the country, it can be explained by the second coefficient b1=0.02. This means that, assuming that all the other variables remain constant, for each increase in the number of population of the country by 1000 people, the total number of crimes in that country increases by 20. This is why in the countries with a high number of population, the level of criminality is higher than in other countries.