THE INFLUENCE OF TOURISM DEVELOPMENT ON THE ECONOMIC STRUCTURE OF THE POPULATION OF BELGRADE

The paper analyzed the impact of tourism development on changes in the employed population in the service sectors by individual activities. The aim of this paper is to point out the relationship between changes in the number of tourists and changes in the number of employed population in service activities. The area of research is limited to the territory of the city of Belgrade. It cover an area of 3.223km2. The basic methodological procedures used for research are mathematical – statistical methods: Pearson's correlation coefficient (r), testing the significance of the correlation coefficient (t test) and causal relationship (R). By applying the mentioned methods, a strong connection has been established between the growth of tourist traffic and the growth of the number of employed population in the service delivery activities on the territory of Belgrade.


Introduction
The development of tourism has a great influence on the transformation of the territory. It is important segment of economic development considering the economic, environmental and sociological changes it brings to the environment. The capital cities represent a significant part of the country's tourist wealth, because in most cases they unite numerous features of their country. The great influence of city tourist centers has a special significance for foreign tourist development (Вујовић, Цвијановић и Штетић, 2011).
The starting hypothesis in this paper is that the growth of tourist traffic affects the changes in the economic structure of the population of Belgrade. The territory of the research is limited to the administrative border of Belgrade, which consists of 7 urban and 10 suburban municipalities. Using mathematical -statistical methods, the connection between the growth of tourist traffic and changes in the numerical and percentage share of the employed population of Belgrade in service delivery activities will be investigated and established.
The analysis of the economic structure of the population of Belgrade includes the number of employed population in accommodation and catering service, administrative and support service activities and other service activities. Important data are also changes in the total number of working population, whose numerical parameters are single out in order to analyze changes in the percentage of the population of employees in service activities compared to the total number of employed population. Bu analyzing the percentage share of the population in the activities of providing services, it is posible to establish how the development of tourism modifies the economic structure of the population of Belgrade.
Analysis of tourist parameters at the level of Belgrade were monitored changes in the number of registered arrivals, the number of registered overnight stays and the average length of stay of tourists for the period from 2011 to 2018. An important component of this analysis is the segmentation of tourists into domestic and foreign in order to perceptions the tourist contract zone of Belgrade. The growth of these indicators, especially foreign tourists, implies positive trends in the tourism of our capital.
By applying statistical methods, the paper establishes changes in the number of employed population in servise activities depending on the growth of tourist traffic. It is based on establishing a relationship between the mentioned parameters (Pearson correlation coefficient), the share of common characteristics between sets of quantitative parameters (causal relationship) and significance level between these relationships (t test). The comparison is made individually between the number of recorded tourist arrivals (as an independent variable X) with the number of staff employed in accommodation and catering services, administrative and support service activities and other service activities (as dependent variable Y). On the basis of statistically obtained values, it is posible to establish the degree of connection between the growth of tourist traffic and oscillations in the number of inhabitants employed in service activities. Using the same statistical procedures for the same time series (2011)(2012)(2013)(2014)(2015)(2016)(2017)(2018), individual graphic analysis shows differences in the impact of tourist traffic on individual service activities.

Field of research and methodology
The research area includes the territory of the city of Belgrade, which includes 7 urban and 10 suburban municipalities: Barajevo, Voždovac, Vračar, Grocka, Zvezdara, Zemun, Lazarevac, Mladenovac, Novi Beograd, Obrenovac, Palilula, Rakovica, Savski Venac, Sopot, Stari Grad, Čukarica and Surčin. The total area with the listed municipalities is 3.223 km 2 . Belgrade has a favorable strategic (in the past), economic, traffic, tourist, political and functional location. It originated and developed at the confluance of the Sava and the Danube river, at the contact of the Pannonian plain and the northern part of the Šumadija hills (Станковић, 2013; Станковић и Гајић, 2019).
The application of statistical methods is the framework of the research process in this paper. The basic methods used in this paper to analyze the impact of tourism development on the active population of Belgrade employed in the service delivery sectors are Pearson's correlation coefficient and causal relationship. The values of the Pearson correlation coefficient range from +1 to -1 depending on the degree of interrelationship between the examined quantitative variables. The correlation coefficient between the examined variables can be positive or negative, with gradation of bond strenght (weak, medium, strong, perfect) based on the obtained values of r coefficient. The calculation of the correlation coefficient (r), on the basis of which the data were processed by years, is performed using the formula (Bluman, 2009;Spiegel, et al., 2001;Treiman, 2014): The character n represent the number of years during the comparison was made (in this study 8, because the data comparison period covers the period from 2011 to 2018). The X variable represent an independent variable, in this case the number of tourists, because based on changes in these values, changes in the number of employees by individual service sectors are determined and the total number of employees in service activities (Y variable).
By applying this method, it is posible to examine the degree of connection between the growth of tourist traffic and changes in the number of employees in service activities. A connection has been established between the number of registered tourist arrivals by years and the total number of the population of Belgrade employed in service delivery activities. A connection has been established between the number of tourists and the number of employees in individual activities related to the service delivery activities: in accommodation and catering services, administrative and support services and other service activities. The aim of this research is to establish which service delivery activities are most affected by the increase in tourist traffic.
Testing the significance of the correlation coefficient is an important segment of this statistical analysis, because it represents an upgrade of the statistical procedure of the obtained values by calculating the correlation coefficient. The value of the significance level was obtained by reading, with the help of the formula the value obtained, from the F table. It is carried out in order to check the significance of the interrelation of the examined variables by the method of correlation coefficient, using a formula (Treiman, 2014): The causal relationship (R) indicates the percentage share of the common characteristics of the X variables and the Y variables. In this study, variable X represents the number of registered tourists in Belgrade. The Y variable represents the total number of employees in the service delivery activities and the number of employees by individual activities. The formula used to calculate the causal relationship is (Bluman, 2009;Spiegel, et al., 2001;Treiman, 2014): The period of monitoring the connection between the mentioned two categories (tourist traffic and employees in service delivery activities) covers the period from 2011 to 2018. Data on the number of tourists and the total number of employees by activities were taken from publications that have a statistical database with the economic structure of the population and records of tourist indicators. Based on a set of data on the economic structure of the population, only those quantitative data related to service delivery activities were selected.

The population of Belgrade employed in service activities
The economic structure of population is an indicator of the economic orientation of a certain territorial unit. Tourism is a modifier of the economic structure by influencing changes in the number and percentage of the active population in service activities (Девеџић, 2011).
Based on eight-year data on the total number of population employed by service sectors, changes are observed (Table 1) The number of employees in administrative and support service activities is also in constant growth in the period from 2011 to 2018 (Table 1) The number of employees in other service activities fluctuated during this period (Table 1). Compared to 2011, when the number of employees in other service activities amounted to 7.746, in 2012 it increased to 7.998. There was decline in 2013 when it amounted to 5.259, and in 2014 it was increased to 5.461.  Based on the individual number of employed population in the activities of accommodation and catering services, administrative and support service activities and other service activities, the total number of employees in activities related to the service activities was calculated, as well as the changes in the percentage share of that population in relation to the total number of employed population in Belgrade.
The number of employees in service activities has been constantly increasing during this eight-year period (Graph 1). In 2011, 33.959 people were employed in the service sector, and due to its constant growth, in 2018 the number of employees was 111.476. In the period from 2011 to 2014, the number of employees gradually grew. The largest increase in the number of employees in service activities followed in the period between 2014 and 2015, when this number increased by 45.373. In 2018, the number of employees in service activities was higher by 77.517 compared to 2011.
Based on the analysis of the percentage share of the number of employees in service activities in relation to the total number of employees in all activities in Belgrade, there is an increase in the share of the population in service activities. In 2011, 5,9% of the employed population performed jobs in service activities, 6,4% in 2012, 6,7% in 2013, 7% in 2014, 12,6% in 2015, 13,5% in 2016, 13,9% in 2017 and 15,5% in 2018. The sharp increase in the number of employees in service activities between 2014 and 2015, was also reflected in the share of employees in the total population, when it increased by 5,6%. Compared to 2011, the percentage of the employed population of Belgrade in service activities in 2018 increased by 9,6%.

Tourist traffic of Belgrade
Belgrade is the largest tourist center in Serbia and this metropolis has a Balkan, European and world tourist contract zone. Belgrade is the seat of business, congress, transit and event tourism in Serbia (Јовичић, 2009; Станковић, 2013; Станковић и Гајић, 2019).
Data related to indicators of tourism development in Belgrade include an analysis for the period from 2011 to 2018, related to the total number of arrivals, overnight stays and average length of stay and their individual values broken down into domestic and foreign participants in tourism. Based on the general assessment of changes during the monitoring period, positive trends in the tourist development of Belgrade are observed.
The number of recorded tourist arrivals in Belgrade is constantly growing ( Table 2). In 2011, the city of Belgrade was visited by a total of 619.124 tourists. In 2018, this number was almost doubled (1.160.582 tourists). In the last 3 years of the series, a significant increase in tourist arrivals haas been recorded. The largest influx of tourists was recorded in 2018, when the number of arrivals in- Belgrade is characterized by a short average stay of tourists, which is a feature of city tourism. In the period from 2011 to 2018 the average length of stay of tourists in Belgrade is 2,1 days. The lowest average length of stay of tourists was recorded in 2014 and 2016 (2,04 days), while the highest average length of stay was in 2012 (2,17 days). Average length of stay of domestic tourists for the period form 2011 to 2018 is 2,5 days. The highest average length of stay of domestic tourists was recorded in 2011 and 2012 (2,6 days), while the shortest length of stay was in 2016 (2,3 days). Average length of stay of foreign tourists for the period from 2011 to 2018 is 1,99 days. The highest value of 2,1 days was recorded in 2018, while in other years those values were 2 days (2011, 2012, 2015, 2016 and 2017) and 1,9 days (2013 and 2014). The conclusion is that the foreign tourists stay in Belgrade for a very short time.  , 2013., 2014., 2015., 2016., 2017., 2018., 2019., Републички завод за статистику

The impact of the growth of tourist traffic on the employment of the population in the service sector and in individual service activities
A cause and effect relationship has been established between changes in the number of recorded tourist arrivals and the oscillation in the number of employed staff by individual service activities (accommodation and catering services, administrative and support service activities and other service activities) and between the number of tourist arrivals and the total number of employees in service activities. Using Pearson's method for calculating the correlation coefficient, a causal relationship between the mentioned parameters and the level of significance between the examined variables was established.

The impact of tourist traffic on the total number of employed population in the service sector
Graph 2 shows the dynamics of the number of employed population in the service sector depending on the oscillation of tourist traffic. Data on the number of employed population include the total number of employed in accomodation and catering services, administrative and support service activities and other service activities. The growth in the number of tourist arrivals in Belgrade is accompanied by an increase in the number of employees in service delivery activities. The correlation coeficient with the value r=+0.92908 at the significance level p≥0.01, suggest a strong positive linear relationship between the investigated two parameters. The causal connection between changes in the number of registered arrivals and the total number of employed population in the service sectors is 86,32%.

The impact of tourist traffic on the number of employees in accommodation and catering services
Graph 3 shows the changes in the number of employed population in accommodation and catering services depending on the growth of tourist traffic. The growth in the number of tourists is reflected in the increased number of employees in this activity. The correlation coefficient with the value r=0.93076 at the significance level p≥0.01 suggest a strong positive linear relationship between the growth of tourist traffic and the increase of employees in accommodation and catering services. The causal connection between the examined two indicators is 86,56%, which indicates a large share of common elements and a high degree of interdependence.

The impact of tourist traffic on the number of employees in administrative and support service activities
Graph 4 shows the changes in the number of employed population in administrative and support service activities as a consequence of the growth of the recorded number of tourist arrivals. A positive correlation was established between these two set of quantitative indicators, which means that the increase in the number of tourists was reflected in the increase in the number of employees in this activity. The corelation coefficient value r=0,96026 with the significance level p≥0.01 implies a direct very strong linear relationship between the data on the growth of the number of tourist arrivals and the number of employees in administrative and support service activities. The causal relationship between the investigated parameters is 92,21%. In relation to other service activities, the highest degree of connection is established right here. Graph 5 shows the changes in the number of employed residents of Belgrade in other service activities depending on tourist traffic. Using an identical methodological procedure, a positive correlation was established whose coefficient correlation is r=0.8240 at the level of significance p≥0,02. This value suggest a direct very strong linear relationship between the growth of tourist arrivals and the number of employees in other service activities. The causal relationship between these two parameters is 67,91%. Compared with the previously obtained values of the correlation coefficient and the causal relationship, the lowest degree of correlation was identified between the growth of tourist arrivals and the number of employees in other service activities.

Graph 5. The relationship between tourist traffic and the number of employees in other service activities
Source: Општине и региони у Републици Србији 2012-2019, Републички завод за статистику Statistical analysis of quantitative parameters on the number of tourist arrivals and changes in employees according to activities related to the provision of services for the time series from 2011 to 2018, certain mechanizms established. Based on comparative representations of the result obtained using the method of Pearson's correlation coefficient and the value of the causal relationship, a direct very strong relationship (range 0,8 ≤ r < 1) was identified between the increase in the number of tourist arrivals and the increase in the number of employees by individual activities (accommodation and catering services, administrative and support service activities and other service activities) and the total number of employees in service activities.
The largest relationship between the examined variables was established between the increase in the number of tourists and the increase in the number of employed staff in administrative and support service activities (with r=0,96026 and R=92,21%). The smallest connection (although statistically significant considering also a direct very strong linear connection) was established between the growth of tourist traffic and changes in the number of employees in other service activities (r= 0,8240 and R=67,91%). The relationship between the number of tourists and the total number of employees in all service activities implies on direct very strong relationship (r=0,92908 and R=86,32%).

Conclusion
An individual analysis of the economic structure of the population of Belgrade and tourist indicators for the period from 2011 to 2018, certain causal link established. In the term of employed population, an increase in the number of employed population since 2014 has been observed. The total number of employed population in service activities is also growing in both numerical and percentage share in the total number of working population (increase by 9,6% during the eight-year period). The analysis of tourist indicators established an increase in the recorded number of tourist arrivals and the number of overnight stays, while no significant progress was recorded in terms of the average length of stay of tourists. There is a trend of increasing the share of foreign tourist clientele in tourist traffic and the number of overnight stay, but it is also noticeable that average foreign tourists stay much shorter than domestic tourists.
The initial assumption was that the growth of tourist traffic is reflected in the economic structure of the population of Belgrade, increasing the numerical and percentage share of the working population in the service delivery activities. An individual analysis of the economic structure of the population of Belgrade and tourist parameters and the application of statistical methods of Pearson's correlation coefficient, testing the level of significance of the correlation coefficient and causal relationship established a very strong relationship between these two series of figures. Using these statistical models, the initial hypothesis was confirmed, which means that the growth of tourist traffic at the same time affect the growth of the working population in service activities.
By establishing a cause-and-effect relationship between tourist traffic and the working population in service activities, it is possible to predict the changes that will occur in the economic structure of the population of Belgrade. If the growth of tourist traffic continues at this pace, investments in tourism of the city will be necessary, which will affect the greater need for employees in tourism activities, which will gradually take an increasing share of service activities in the total number of employees.