Why labor migrate from one place to other?

Economists believe , in any market where Marginal Prodictive is higher, there wage rate is higher and MP and Wages have direct relationship , so labor moves to the market where MP is high along this wages are high 

Certainly in order to find the best job opportunities.

I believe there are different factors involved which creates a tendency among the people to migrate or causes their displacement. Some of the prominent factors and causes are as follows:

1. To Seek or Avail Oppurtunities (latest deveopment and other projects are launched which attaracts people from far around);

2. To get benefits out of Economical Differences (currency rates of different countries matters);

3. Shortage of Labour in Target Country (labour services are not locally available in many developed countries);

4. Personal Dissatisfaction (there may be some personal domestic or family issues dissatisfying one and forces him to move);

5. Maximum Efforts & Minimum Rewards (in most of under-developing countries, labour is not being paid according to their efforts and services; even after services in odd hours they are unable to survive);

6. Lifestyle (lifestyle of different countries usually causes to attract even labour class of other countries), etc.

Either to escape poverty or to escape war or to improve the standard of living