Theories of Migration.

   THEORIES OF MIGRATION 

        Several theories & laws have been postulated by geographers about the patterns of migration. There is how, not a single reason behind the migration. Some of the important laws & models of human migration have been described beautifully in the following- 

 RAVENSTEIN’S THEORY OF MIGRATION 

                                                   

INTRODUCTION:- The quantitative revolution in geography in the early 1960s brought a new realization among the geographers and stimulated them to formulate theories and models. The task of theory-building and model-development is not easy for population geographers, who deal with Human phenomena which are highly dynamic and which change in their spatial and temporal dimensions with unusual rapidness. Moreover, it may be difficult to subject individual human behavior to a well-defined set of laws. The preceding pages have highlighted that the phenomenon of migration 1st a highly complex phenomenon and the factors associated with the movements of people are still more complex. In this context, one is reminded of Humphrey's observation that migration was rather distinguished for its lawless than for having a definite law. 

       The first scholar to formulate the laws of migration was E.G. Ravenstein who based his generalizations on empirical studies of population movement in Britain, the United States, and some of the countries of North-West Europe. He observed the migration data between 1885 and 1889 and arrived at certain very important conclusions which may be taken as the laws of migration. Subsequently, other leading scholars like Lee corroborated his findings and added some new laws of migration. 

     The first formal attempt on theoretical formulations on migration was made by Ravenstein in 1885 when he gave the following laws of migration, which he derived from an analysis of intercountry movements within Britain in the 19th century using census birthplace data, based on certain 

ASSUMPTIONS;- 
i. REASONS FOR THE MIGRATION  

ii. DISTANCE 

iii. CHARACTERISTICS OF THE MIGRANTS 

1. Migration and Distance:- A large number of migrants move to a short distance only...there takes place consequently, a universal shifting displacement of the population which produces 'currents of migration set in the direction of great centers for commerce and industry which absorb the migrants. Implied in this is (i) distance decay function; and (ii) preference for large centers of commerce and industry area-long-distance migrants. That’s why it was also known as distance decay law/distance migration law. 

2. Migration by Stages:- The inhabitants of the countryside surrounding a rapidly growing town flock into it; the gaps, thus, created in the countryside are filled up by migrants from remoter areas until the attractive force of one of the rapidly. Growing Cities makes its influence felt, step by step, to the most remote corner. The process of dispersion is the inverse of that of absorption and exhibits similar features. 

3. Streams and Counter-streams:- Each main current of migration produces a compensating counter-current, in lesser strength. 

4. Rural-Urban Differential:- The natives of the towns have a low degree of propensity to migrate in comparison to their counterparts in the countryside. 

5. Preponderance of Females:- Among the short-distance migrants, females appear to predominate. Sometimes it also acts as push-back migration/reverse migration. 

6. Technology and Migration:- The magnitude of migration increases with the advancement of technology. 

7. Motives behind Migration:- Economic motives have primary importance among various factors governing the magnitude of migration. 

8. Most migrants are adults, families nearly moved out of the country of birth. 

9. the Last town will grow, where the people are mostly migrants than the natural increase. After the revised edition of 1st synopsis, he added another two laws, 

10. Volume of migration increases as secondary and tertiary activities develop and transportation facilities improve {INDIA}. 

11. Major direction of migration is from agricultural areas to centers of commerce and industrial areas common than other migration directions worldwide.   

Most of the laws forwarded by Raven stein seem to have stood the test of time. Pryor (1969) found these laws to be largely valid in his study about the experience of Malaysia and other countries. 
CRITICISM:- Although the above statements of Ravenstein have been modified by the subsequent researchers, they have not been disproved. The main criticism of Ravenstein's laws of migration are:- 

i) He neglected various forms of forced migration. 

ii) He failed to count for the current exodus from some large cities to smaller places in the developed countries. 

iii) His approach is positivistic based on data. He ignored the normative, cultural legions and traditional values of the people and their likes, dislike, prejudice, and aesthetic values. 

      Despite all these omissions and commissions, Ravenstein's laws of migration have great validity and are largely applicable all over the world. 

 LEE’S THEORY OF MIGRATION 

INTRODUCTION: - Migration is one of the distinguishing features of human beings that has been occurring since it started from the very beginning of man’s appearance in this universe. Migration is one of the causes of social change and it is one of the three basic components of demographic change, the other two being birth and death.     After Ravenstein’s migration theory, Everett lee gives another theory on migration in 1966. Everett Spurgeon Lee, Professor of Sociology at the University of Georgia is known for his pioneering theory of migration, and this migration theory is known as “Lee’s migration model” or it is also known as “push-pull theory of migration”. 

CAUSES OF MIGRATION:-  According to Lee, there are two reasons for people to migrate. Either there is a push factor, (that are linked with the origin region) that could be poverty, political instability, climatic disturbances, poor healthcare, loss of wealth, etc motivate people to move out from the region. Another reason is to pull factors,(that is linked with the place of destination) which motivate the people to come in or move in, that could be the good economy, job opportunities, better health facilities, political and/or religious freedom, better transportation and communication facilities, etc. 

MAIN SUBJECT OF THE THEORY:- Lee elaborates in between push and pulls region or origin region to a place of destination there are intervening obstacles or opportunities. Here obstacles are in the form of mountains, sea, river or geographical barrier, political barrier, economic barrier, etc. On the other hand, opportunities mean different types of facilities, like - transport facilities, other facilities. 

 

             Now both the region push and pull have different factors, it may be positive factors (+) (that can attract the people) or it may be negative factors (-). In this Lee's model, the number of positive factors is much more in the pull region as compared to the push region. Similarly, on the other hand, negative factors are more in the push region than the pull region. Then there would be curtain neutral factors (•) are found in both the region, (natural factors means, it exists in both the region, either in push region and pull region. For example - the transportation system is good in both regions, climatic conditions are good or the same in the push region as well as in the pull region. 

   Lee also explained, personal factors also affect migration. Like - marriage, educational factors, etc. 

ASSUMPTIONS OF THE THEORY:-  So this theory basically focused on four characteristics or assumptions. These are –– 

  Factors associated with the area of origin.  
  Factors associated with the area of destination. 
  Intervening obstacles/opportunities. 
  Personal factors or the people's own choice.

CRITICISM: -Although the push-pull theory has been acknowledged as a path-breaking model that explains migration at various periods and has stood the test of time, it has also faced criticism. Moreover, the presence of intervening obstacles does not help demographers to identify which factors have major influence and which ones are minor factors. For this reason, Lee’s theory offers little practical guidance for policy and decision-making in developing nations. 

CONCLUSION: - At the end of the conclusion we can say, this theory is more or less important in recent/present or today's scenario. Otherwise, this theory was very much popular as well as important at the time when this theory was written. 

 WILLIAM JOHN REILLY’S THEORY OF MIGRATION    

INTRODUCTION:-Population Geography is purely a social science. In social sciences, particularly in population studies, the task of theory and model building is not easy because human & social phenomena are highly dynamic and have a tendency to change in their spatial & temporal dimensions without any proper regularity. To consider the individual human behavior to a well-defined set of laws is not an easy task for population geographers. The phenomena of migration & the elements associated with migrants are very complex in this context, migration of population is rather known for its lawlessness than for having any definite laws. Despite the high complexity of migration phenomena, some scholars have tried to formulate the process of migration  Some recent efforts in this field are quite encouraging.  

                    In the field of formulation of theory & model building for the migration process, an early but important effort was made by E.G. Ravenstein(1889). W.J.Reilly(1931), E.S.Lee(1996), W.Zelinsky(1971), Wolpert(1975), Gould and Prothero(1975), etc. have also made their contributions in the field of model-building concerned with the migration process for describing & interpret the migratory behavior of human being. 

BACKGROUND:-  

        One of the most important contributions of geography in the field of migration analysis is concerning the relationship between distance & migration. A clear & persistent inverse relationship between the two has been established in several studies. The role of population size & distance in determining the spatial interaction had become formalized in1930s & the 1940s when Newton’s law of gravitation was first pointed out the isomorphic relationship of population moments, which later come to be known as the Gravity Model, yet is it believed that W.J.Reilly had already postulated that the moment of persons between two urban centers would be directly proportional to the product of their population and inversely proportional to the square of the distance between them. 
AIMS: -Some overall aims are as follows- 

1) To empower and support migrants, particularly those who are most vulnerable so that they feel safe and confident to navigate the complex migration challenges, maximize opportunities and fulfill their full potential. 

2) To promote migrant rights and strengthen social cohesion in Leeds. 

3)To challenge and reduce the effects of policies that create a hostile environment for migrants and advocate policies and practices that promote the rights, safety, equality, and dignity of migrants. 

4) Help other organizations/services/groups to enhance understanding of migration issues to better meet the needs of migrants. 

OBJECTIVES:-  

        The main objectives are beautifully mentioned below- 

1) To help migrants make informed positive choices through the provision of information, 

guidance and support. 

2) Improve access to Justice through signposting and referrals to legal/immigration services and casework support. 

3) Provide advocacy support for migrants especially for the most vulnerable to ensure their rights are protected. 

4) Facilitate access to mainstream provision including healthcare, employment, etc. 

5) Reduce the effects of poverty, destitution, and social exclusion among vulnerable migrants by supporting access to provision and humanitarian assistance. 

6) Raise awareness and develop an understanding of migration issues to build a society where services are knowledgeable and competent in meeting the needs of migrants. 

BASIC CHARACTERISTICS:-   

     Some major characteristics of this theory are respectively mentioned below- 

1) Uniform topography, 

2) Uniform political boundaries, person preference & transportation, 

3) No man-made boundaries (this would discourage migrating). 

ASSUMPTIONS OF THIS THEORY: -

         W.J.Reilly has postulated that the interaction between two places was direct product such as – 
1) Distance of the town: -The distance displays a negative association with the gravitational force of the town (Negatively related between distance & gravity; its value varies between 0 to 1).
2) Mass of the town: -Demographically, it’s referred to the total people. In Reilly’s model, the force of the town ‘A’ as a nodal region that displays homogeneity in terms of their functionality is the population size of the same town. The population of any town is positively associated with the influence of that same time (Positively related between population size & gravity due to the better opportunities in the industry, commerce, etc. 

MEASUREMENT OF THIS THEORY:-    

Mathematically, it is expressed as – 

Db=Dab/(1+√Pa/Pb)         [In this demarcation will be from smaller town] 

Where, Db=Influence/breakpoint between towns, 

      Dab=Distance between town A & town B, 

       Pa=Population of town A (Large town), 

       Pb=Population of town B (Smaller town). 

If we take the smaller town (A) more influential then the formula will be reversed in respect to the demarcation of a large town (B). 

For example, If we take the population of town A is 131000, the Population of town B is 75000, and the distance between them is 71 kilometers, then 

                       Db=Dab/(1+ √Pa/Pa) 

                            =71/ (1+131000/75000)         

                            =31(Rounded). 

  Therefore, we can easily say that 31 kilometers always from a smaller town will be a benchmark/threshold limit between towns A & B. 

Fig.W.J.Reilly’s Theory of Migration 

CRITICISM & APPLICABILITY: - 

Some critics have criticized this theory which has respectively mentioned below – 

1) This model is very much suitable for generation ‘X’ & ‘Y’ but not generation 'Z' where the virtual world/social media plays a very important role as the people are sitting physically at one place but acting/doing important activities in other places. 

2) This model is also suitable for transport/traffic management, town planning like Kolkata metropolitan region, national capital territory regions such as Delhi. 
CONCLUSION/MY COMMITMENTS:- 

        Different migration theories have stressed different aspects of migration-economics (wages, vacancies, and unemployment), social (social mobility, social status), and environmental (residential satisfaction) among others. During the colonial period (British period) millions of Indian laborers were sent to countries such as Mauritius, Caribbean islands, Fiji and South Africa by British from Uttar Pradesh and Bihar to work as plantation workers. In the 20th century, semiskilled Indians migrated to neighboring countries such as Thailand, Malaysia, Singapore, Indonesia, Brunei, and African countries as artisans, traders, and factory workers. In recent times, professionals like doctors, engineers, software engineers, management consultants, financial experts, media persons, migrated to countries such management consultants, financial experts, media persons, migrated to countries such as the USA, Canada, UK, Australia, New Zealand, and Germany, etc. These professionals are highly educated, the highest-paid. Despite the many different approaches to the analysis of migration, there is a common consensus; all researchers seem to agree that people or households migrate to improve their situation, or, more precisely, to be better off in the new location in the future than they would be in the old place of residence.