I am not running any industry. But as a consultant to many manufacturing industries, I have some idea about the queries raised in the post. Therefore, I do hope that the poster would be magnanimous enough by not asking for the source. The following are my extempore thoughts only on the moment I read the query:
First and foremost, Tamilnadu is one among the States having the best educational infrastructure. Particularly, the mushroom growth of engineering colleges across the State in the last three decades feeds the needs of developing IT industries and other ITES establishment both within the State and outside it with young engineering graduates who are mostly from the middle class families. In the absence of this situation, most of them would be banking upon Central and State Governments only for employment opportunities or would have stepped into the shoes of their fathers by taking whatever jobs available in their local industries. Therefore, a sizable chunk of youth who would have formed part of the unskilled or manual labor force got shifted to the skilled category. The IT field being a versatile one absorbs even non-IT engineering graduates in its various activities like software development, testing, trouble shooting etc. The modernisation of manufacturing industries like textiles, sugar, cement has converted their labor-intensive character to a considerable extent. Added to this is the boom in the construction industry demanding more no of manual labor. In so far as the remaining unskilled local labor force is concerned, most of them have developed a sense of complacency by the lure of state- provided freebies and the chance of earning easy money through the rural employment guarantee programmes in almost all seasons like floods or famines and do not come forward to hard labor. The steadily increasing addiction to alcohal among the youth is another indication of lower productivity of the existing unskilled workforce in Tamilnadu.
Whereas, the picture in the northern States like MadhyaPradesh, Bihar, Jharkand, Orissa etc and the North East is totally different. Rural development, education, public health simply remain in the papers only. Socio-economic conditions like illiteracy, poverty, frequent alternate natural disasters like floods and famines, naturally compel the working masses to resort to large scale migration in search of livelihood to economically advanced regions of the country.
The comparative wages for unskilled labor is higher in Tamilnadu and the people of the State accept the north indian labor without any inhibitions. Since the infrastructure in communication, transport etc are relatively better than any other part of the country, the mobility of the migrant workmen is easier both back and forth. Enforcement of labor laws, environmental safety and protection of human rights are relatively better, labor exploitation is kept to the minimum.
The community of interest of the migrant workmen, their hard work, their cordial behaviour with the local employers and workforce, timely delivery of work, their simple lifestyle and technical expertise in certain kinds of works make them more welcome in Tamilnadu.