=Paper= {{Paper |id=Vol-1623/paperapp13 |storemode=property |title=Migration Processes Modeling with Cellular Automation |pdfUrl=https://ceur-ws.org/Vol-1623/paperapp13.pdf |volume=Vol-1623 |authors=Yuriy Shmidt, Natalia Ivashina, Galina Ozerova, Paul Lobodin |dblpUrl=https://dblp.org/rec/conf/door/ShmidtIOL16 }} ==Migration Processes Modeling with Cellular Automation== https://ceur-ws.org/Vol-1623/paperapp13.pdf
                      Migration Processes Modeling
                       with Cellular Automation

                Shmidt Yu. D., Ivashina N.V., Ozerova G.P., Lobodin P.N.

                      Far Eastern Federal University, Vladivostok, Russia
                    {syd, ivashina.nv, ozerova.gp,lobodin pn}@dvfu.ru



       Abstract. The problem of interregional migration flows modeling is being stud-
       ied. The conjecture that modeling household migration behavior at local level in
       view of community interactions and using cellular automata results in adequate
       forecasting of interregional migration flows has been numerically confirmed. A
       computer program was developed in order to implement the cellular automaton
       suggested in this study, which models interregional migration flows. Cellular
       automaton program was tested on Primorsky krai migration flows statistical
       data; a short-term forecast of the region migration flows was obtained.

       Keywords: Modelling, migration, cellular automaton, regions, forecasting, mi-
       gration flow, software package.


1    Introduction

Migration processes are complex dynamical phenomena influencing the population re-
production and its distribution across the territories. They are affected by many socio-
economic factors having stochastic and probabilistic character. Migration makes a sub-
stantial impact on the demographic structure, regional and local labor markets. There-
fore, forecasting quantitative and qualitative migration indices and their consequences
is a very important and critical task. In order to carry it out modern mathematical
tools are needed because these processes have a dynamic character at different time
intervals and nonlinear character in terms of interrelation of factors.
    There is a relatively successful experience of Russian and foreign scholars in us-
ing econometric models to describe migration processes [1], [2], [3], [4], [5], [6], [7].
Non-linear dynamical systems are used for population migration modeling along with
traditional econometric techniques [8], [9], [10].
    In order to model population movement a theory of stochastic processes is used
quite successfully. In the work [11] and the majority of succeeding papers on the sub-
ject Markov chains were used as a model for population movement. These were Markov
processes in discrete time. Migration processes are dynamic; they change dramatically
in time reacting to the changes of external environment and population living con-
ditions. This fact narrows down considerably the potential of using Markov models

Copyright ⃝
          c by the paper’s authors. Copying permitted for private and academic purposes.
In: A. Kononov et al. (eds.): DOOR 2016, Vladivostok, Russia, published at http://ceur-ws.org
780     Shmidt Yu. D., Ivashina N.V., Ozerova G.P., Lobodin P.N.

for their modeling on long time intervals because transition probabilities in almost all
Markov models are assumed to be constant.
    In the present work it is proposed to use cellular automata for modeling interregional
migration flows. The theory of cellular automata has a relatively short but reasonably
productive history, the main stages of which are outlined in [12], [13], [14], [15].
    In cellular automaton model each cell changes its state as a result of interaction
with a limited number of cells, as a rule with their immediate surroundings. However,
a simultaneous change of the state of all cells, i.e. of the entire lattice, is possible on
the basis of cellular automaton general rule. This characteristic enables to relate the
processes happening at a micro-level with the processes happening at the macro-level
while modeling. This is a crucially important characteristic of cellular automata, which
enables their successful use for modeling systems where three-dimensional interaction
between the elements plays a significant role. They also proved useful in modeling
liquid and gas dynamics in various environments, in modeling systems containing a
great number of particles non-linearly interacting with each other, in describing the
emergence of collective phenomena such as turbulence, order, chaos, symmetry and
fractality violations, etc [16].
    In recent years cellular automata found applications in modeling social phenomena
both as purely theoretical tools for qualitative analysis and for numerical forecasting.
Some examples of cellular automata used in sociological problems and urban migration
have been introduced in [17], [18], [19], [20]. The results of research in the field of urban
migration carried out using cellular automata are presented in [21], [22], where the
possibility of using cellular automata for analyzing non-linear dynamic interaction of
households was emphasized. The possibility results from simplicity of implementation
of household interaction models on micro-level as well as from the ability of such
models to take account of the influence of macroeconomic conditions on the modeled
processes. In particular, cellular automaton models developed in [22] include the rules,
which control the decisions of households to move to a different area of the city. Each
household possesses a social structure represented by a summary indicator reflecting
some common characteristics of a household: average age of residents, average income,
employment status, etc. The decision to move is made when there is a substantial
difference between the social status of a household and an average social status of its
neighborhood.
    In general, cellular automata models have many positive qualities, which undoubt-
edly influence the intensity of their use in different branches of science. However, there
are certain negative features restraining the development of this area of mathematic
modeling, among those it is important to mention a weak general theoretical basis of
cellular automata, insufficient convergence results for simulations using some types of
cellular automata, the problems of robustness of numerical solutions.
    The goal of this study is to develop a cellular automaton model that could be
successfully applied for modeling interregional migration flows. The analysis of existing
migration models shows that, despite a wide range of available models, most of them
use only aggregated data. This leads to a certain discrepancy between the behavior of
economic entities at a micro-level corresponding to empirical data and the projected
figures of migration at macro- and meso-levels.
                            Migration Processes Modeling with Cellular Automation        781

    The assumption of the present study is that the modeling of household behavior
with regard to their migration decisions at local levels performed by cellular automata
allows to achieve adequate forecasts for interregional migration flows.


2    The cellular automaton model description
A cellular automaton is a finite collection of objects (cells) which, as a rule, form a
regular lattice. In other words, without using strict mathematical terminology, this is a
collection of cells joined together in a specific way to form a uniform lattice. The state
of the i-th cell at time t is described by a number or a vector which we denote a(i, t).
The collection of states of all the cells is called the state of the lattice. In the cellular
automaton model, each state of the lattice corresponds to a certain point of time that
changes in discrete steps. The state of the lattice changes according to a certain law
that is called the rule of the cellular automaton. The rule determines a cells state at
the time t + 1 based on its states and the states of other cells at time t. This can be
expressed mathematically by the following formula:
                                                      ∑
                            a(j, t + 1) = F (a(j, t),     a(i, t)),                       (1)
                                                   i∈Q(j)

    where F is a function that describes the corresponding rule, Q(j) is the set of
cell numbers that influence the state of the cell j in time period from t to t + 1.
Theoretically, cell automata may have any dimension. However, it is one- and two-
dimensional automata that are most often used. In 2-dimensional cellular automata,
the lattice is represented by a 2-dimensional array, and each cell is numbered with an
ordered pair of numbers (a, b). In this case, the cells closest neighbors are either those
having a common side with the initial cell (the von Neumann neighborhood), which
produces 4 neighboring cells for a rectangular cell, or those having common vertices
with the initial cell (the Moore neighborhood), which gives 8 neighboring cells.
    The classical cellular automaton model has the following features:
 – the lattice of a cellular automaton is homogeneous, i.e. the transition rules are the
   same for all the cells;
 – the set of states is finite for each cell;
 – a cell can be influenced only by cells from its neighborhood, i.e. its closest neighbors;
 – the states of all the cells change simultaneously at end of an iteration.
    Various criteria exist for classification of cellular automata. In particular, based on
the transition rules, they can be classified as deterministic or probabilistic. In deter-
ministic cellular automata, the state of each cell at time t + 1 is determined univocally
by the state of this cell and its closest neighbors at time point t. The corresponding
rule is represented by formula (1). A cellular automaton that determines its states
based on certain transition probabilities is called probabilistic. In this case, the rule for
transition from the state a(i, t) of a cell i into the state a(i, t + 1) can be written as
follows:                                                ∑
                         P = P (a(j, t + 1) | a(j, t),       a(i, t)),                    (2)
                                                     i∈Q(j)
782       Shmidt Yu. D., Ivashina N.V., Ozerova G.P., Lobodin P.N.

where P is the probability of the j-th element transitioning from the state a(j, t) into
state a(j, t + 1) given certain states of its neighbors.
    In a modern world, the decision of a household to move can be influenced not only
by its closest neighbors, but also by randomly located agents. To model this situation
one might use a cellular automaton that accounts the states of 8 or 4 randomly chosen
cells on the lattice when determining the state of each cell. However, in a more realistic
model both the opinions of the closest neighbors and the remote agents contribute to
the migration decision. To this end, it is possible to use the combined probabilistic
cellular automaton introduced in [16], where the state of each cell is determined by on
the states of its 4 closest neighbors (the von Neumann neighborhood) and 4 randomly
chosen cells.
    When implementing the cellular automaton model, we will use a rectangular lattice
for each Federal district of Russia and the neighboring countries. Each rectangular
lattice contains the same number of cells as the number of households in a given
region, assuming that a household consists of three people. Also, when building a
cellular automaton, it is necessary to specify the rules of its behavior on the boundary
of the lattice. In this paper we will use an automaton with the toric topology, i.e. the
first row viewed as a continuation of the last whereas the last one precedes the first
(the same applies to columns as well).
    We consider probabilities of households leaving a region in 9 directions (Federal dis-
tricts of Russia, the Commonwealth of Independent States (CIS) and countries outside
the CIS). Denote by p0 the probability that a household stays in a given region and
by pi the probability of moving to the i-th region for permanent residence, i = 1 . . . 9.
Estimate these probabilities as averages over a number of years.
    We will form the cells corresponding to a given region as follows. The number of
cells is equal to the number of residents divided by 3, i.e. we assume that an average
household totals three. We assign the initial state by sampling from the uniform dis-
tribution over integers {0, 1, .., 9}. If a cell is assigned 0, then the respective household
remains to live in the region in question for the following period. If the state is i, then
the household leaves for the region i, i = 1 . . . 9.
    Each iteration comprises the following steps:
 1. Detecting the households that decide to leave the examined region.
 2. Detecting the number of households that decide to arrive in the examined regions.
 3. Reviewing the cells in the given region and assigning new states to them.
    During the first step, browse the cells in the lattice that describes the given region.
For each cell, go over its 4 neighbors and 4 randomly chosen cells in the region. Looking
at their states do the following:
 – For each cell, if there is a non-zero state among its neighbors that is encountered
   more often than any other state, then such state is assigned to this cell and it will
   move to the corresponding region.
                                              ∑
                                              m
 – If there is no such state, calculate p =     pij using m neighbor cells in non-zero
                                                     j
      states and their corresponding probabilities pi1 , pi2 , . . . pim . Divide the interval [0, 1]
                                   pi
      into subintervals of length pj , j = 1, m. Generate a random number from the
                           Migration Processes Modeling with Cellular Automation        783

    interval [0, 1] and choose the region of destination according to the subinterval hit
    by this number.
   In view of the states of all the neighboring cells (8 cells) and using Laplaces function,
build the transition probabilities P (n):
                       (                           )       (          )
                                              3                    3
            W (n) = P −3σ ≤ x ≤ −3σ + σn = Φ −3 + n + Φ(3),                              (3)
                                              4                    4
                                        W (n)     0, 9973
                              P (n) =         , k= 9      ,                             (4)
                                         k         ∑
                                                       pi
                                                     i=1
where n is the number of neighboring cells for the current cell in non-zero state; σ is
the mean square deviation; Φ(x) is Laplace’s function.
    This pretty much agrees with the central limit theorem of the probability theory.
According to it, if a random variable represents a sum of a large number of mutually
independent random variables, then it has near-normal distribution. Moreover, the
three-sigma rule is valid for a normally distributed variable: if a random variable is
normally distributed, then with very high probability the absolute value of its deviation
from mathematical expectation does not exceed the tripled mean square deviation.
    Generate a random number . If x < P (n), then the household decides to leave for
the selected region. Memorize the coordinates of this cell. Otherwise, the cell state will
be 0, and the household will not leave.
    In a similar way, on step 2 determine the households that decide to move in the
region under examination, browsing the lattices for Federal districts and the CIS coun-
tries. The probability of leaving for the current region is known for each Federal district
and the CIS countries and is denote g1 . All the cells of the respective lattice have the
state of 0 or 1 depending on whether the household decides to stay in its region or
leave for the examined region, respectively. For each cell, go over 4 neighboring and
4 randomly chosen cells in the region. In this case, the transition probability P (n) is
calculated as follows:
                                        W (n)        0, 9973
                               P (n) =        , k=           ,                          (5)
                                          k             g1
Where n is the number of cells from the neighborhood of the current cell with state 1.
    Generate a random number . If x < P (n), then the household decides to leave
for the region in question. Otherwise, the cell state is 0, and the household will not
leave. For each lattice, calculate the number of newcomers to the region in question
and compute their total.
    During step 3, randomly distribute the households that have arrived to the region
under examination among the cells of the households that have left. The states of
such cells are determined according to the departure probabilities for the examined
region for the current year. Then proceed to step 1 or finish the calculation. During
the learning phase, the number of iterations is determined by the difference between
the calculated value and the actual number of people who left the region in this year.
During the forecasting phase the number of iterations is determined as the average
number of the automatons iterations for one-year modeling over the period of 5 years
during the learning phase.
784        Shmidt Yu. D., Ivashina N.V., Ozerova G.P., Lobodin P.N.

3        The result of the numerical experiment

The cellular automaton described above was tested on the statistical data of Primorsky
krai. The following data is available for the period from 2004 to 2014, which was used as
an input for the computer program that implemented the proposed cellular automaton:

 – population number of Primorsky krai, each Federal district, including the Far East-
   ern (without Primorsky krai) and the CIS countries;
 – vector of average probabilities for migration from Primorsky krai to Federal districts
   and CIS countries and countries outside the CIS by years;
 – vector of average probabilities for migration to Primorsky krai from Federal districts
   and CIS countries by years;
 – in- and out- flow data for Primorsky krai by years.

    The data for the years from 2005 to 2014 was used for the learning of the cellular
automaton. The number of iterations of the cellular automaton required to model one
year migration flow varied within the limits between 61 and 79. The forecasting error
for the total annual outflow from Primorsky krai amounted from 0,08% to 0,72%, total
error taking account of the region of destination – from 4,43% to 7,13%. A considerable
increase of error is largely due to the countries outside the CIS. The number of immi-
grants to these counties was relatively small so that absolute deviation of a few people
accounted for a great percentage of the total error for that region. This is reflected in
the average error for the migration flow in general.
    In order to illustrate the aforementioned we will cite the 2005 data for Primorsky
krai migration flows and their calculated values. The results obtained for that year are
typical. 61 iterations of cellular automaton were run. The calculated total outflow from
Primorsky krai was 12909 people, actual number amounted 13003 people who departed
the region, the error is 0,72%.
    Table 1 shows the actual and calculated migration outflows from Primorsky krai
in 2005. The compound error in forecasting the migration flow by the regions totaled
4,95%.


Table 1. Actual and calculated migration flows from Primorsky krai in 2005, number of
individuals

Number Region                                                    Calculated value Actual value Error, %


    1.   Central Federal district                                      2894          2857       1,30

    2.   North-Western Federal district                                1122          1075       4,37

    3.   Southern and North-Caucasus Federal district                  1287          1310       1,76

    4.   Privolzhsky Federal district                                  1152          1219       5,50

    5.   Ural Federal district                                         625            638       2,04

    6.   Siberian Federal district                                     1851          1834       0,93

    7.   Ear Eastern Federal district (without Primorsky krai)         3507          3631       3,42

    8.   Countries outside the CIS                                     136            150       9,33

    9.   CIS countries                                                 335            289       15,92
                                         Migration Processes Modeling with Cellular Automation          785

    In the present research a short-term forecast of interregional migration outflow from
Primorsky krai for 1 or 2 years has been made. The year 2014 was used as the forecast
base that is 2014 population data was entered into the cellular automaton. The results
of the forecast are presented in table 2.


    Table 2. Projected values of migration flow from Primorsky krai, number of individuals

Number Region                                                     One-year forecast Two-year forecast


    1.    Central Federal district                                      2799             5547

    2.    North-Western Federal district                                1805             3600

    3.    Southern and North-Caucasus Federal district                  1759             3561

    4.    Privolzhsky Federal district                                  990              2009

    5.    Ural Federal district                                         447               861

    6.    Siberian Federal district                                     1573             3322

    7.    Ear Eastern Federal district (without Primorsky krai)         3066             6336

    8.    Countries outside the CIS                                     192               332

    9.    CIS countries                                                 215               339

    10.   Total                                                        12846             25907

    11.   Number of incomers to Primorsky krai                          5860             12670




   In order to model migration flows by a cellular automaton a cross-platform program
using Go language was developed. The calculations were performed on a computer with
quad-core processor Intel Core i7 with clock frequency 2.5 GHz and 16 GB of RAM
memory. The amount of computation made during the experiments was rather big.
On average it took 7 minutes to perform one year calculation. In order to improve the
computation speed it is reasonable to consider the possibility of parallel calculations.
Conclusion



4         Conclusion

The present study shows the possibility and viability of interregional migration flow
modeling by cellular automata. Modeling of migration processes at macro-economic
level based on simulations by cellular automata of household behavior at local level
appears to be a promising research direction. In order to widen the capabilities of the
developed cellular automaton in mid-term and long-term forecasting of interregional
migration flows it is necessary to incorporate birth and mortality processes into a
model. In other words, it seems reasonable to make adjustments for natural population
decrease as well as for migration balance while forecasting the migration flows. The
projected birth and mortality rates can be estimated by an application of econometric
models. This research has been supported by the Russian Foundation for Basic Research
under project 15-56-53032.
786     Shmidt Yu. D., Ivashina N.V., Ozerova G.P., Lobodin P.N.

References
1. Rogers, A.: A Regression Analysis of Interregional Migration in California. The Review of
  Economics and Statistics. 49(2), 262–267 (1967).
2. Haurin, D.R.: The regional distribution of population, migration, and climate. The Quar-
  terly Journal of Economics. 95(2), 293–308 (1980).
3. Andrienko, Y., Guriev, S.: Determinants of interregional mobility in Russia. Evidence from
  panel data// Economics of Transition. 12(1), 1–27 (2004).
4. Gerber, T.: Regional economic performance and net migration rates in Russia, 19932002.
  International Migration Review. 40(3), 661–697 (2006).
5. Sarra, A.L., Signore, M. A.: Dynamic Origin-constrained Spatial Interaction Model Applied
  to Polands Inter-provincial Migration. Spatial Economic Analysis. 5(1), 29–41 (2010).
6. Vakulenko E.S., Mkrtchyan N.V., Furmanov K.K.: Modeling of registered migration flows
  between the regions of the Russian Federation. Applied Econometrics. 1(21), 35–55 (2011).
7. Schmidt, Yu.D.: Prognosis of demand and supply at the regional labor market. Vladivostok
  (2012).
8. Vasiluev A.M.: Model of labor market self-organization. Economics and mathematical
  methods. 37 (2), 123–127 (2001).
9. Korovkin A.G.: Dynamics of labor market and employment: problems of macro-economic
  analysis and prognosticating. Moscow (2001).
10. Havinson, M.Y., Kulakov, M.P., Mishchuk, S.N.: Mathematical model of population dy-
  namics of economically active population and of foreign workers in the region (on the example
  of the Jewish autonomous region). Informatics and control systems. 1 (31), 95–106 (2012).
11. Blumen, I., Kogan, M., McCarthy, P.: The Industrial Mobility of Labor as a Probability
  Process. N.-Y.(1955).
12. Toffoli, T., Margolus, N.: Machines cellular automata. Moscow (1991).
13. Wolfram,        S.:     A       New     Kind        of    Science.        (2002).     URL:
  http//www.wolframscience.com/nksonline/toc.html.
14. Astafjev, G.B., Koronovskii, A.A., Khramov, A.E.: Cellular automata. Saratov (2003).
15. Lobanov A.I.: Models of cellular automata. Computer studies and modeling. 2 (3), 273–
  293 (2010).
16. Schmidt, Yu.D., Lobodina, O.N.: On some approaches to modeling the spatial diffusion
  of innovations// Spatial Economics. 2, 103–115 (2015).
17. Plotinskii, Yu. M.: Models of social processes. Moscow (2001).
18. Batty, M.: Cities and Complexity Understanding Cities with Cellular Automata, Agent-
  Based Models and Fractals, MIT Press, Cambridge, Massachusetts (2005).
19. Cheng, J., Masser, I.: Cellular Automata Based Temporal Process Understanding of Urban
  Growth. Lecture Notes in Computer Science. 2493, 325–336 (2002).
20. Ward, D.P., Murray, A.T., Phinn, S.R.: Integrating spatial optimization and cellular au-
  tomata for evaluating urban change. Regional Science. 37, 131–148 (2003).
21. Benito-Ostolaza, J.M., Hernndez, P., Palacios-Marqus, D., Vila, J.: Modeling local so-
  cial migrations: A cellular automata approach. Cybernetics and Systems. 46 (3-4), 287–302
  (2015).
22. Dabbaghian, V., Jackson, P., Spicer, V., Wuschke, K.: A cellular automata model on resi-
  dential migration in response to neighborhood social dynamics. Mathematical and Computer
  Modelling. 52 (9-10), 1752–1762 (2010).