GATS stands for General Agreement on Trade and Services. This is a treaty under the control and part of the WTO .

The GATS defines four modes of trade in services. Mode 4 refers to the temporary migration of workers, to provide services or fulfill a service contract. Because the current framework of Mode 4 allows for only temporary movement of workers across borders to provide services, and their visa as well as their right to stay and work are tied to their original terms of employment or contract and to their employer.

The WTO is basically negotiating a global guest worker program.

Public Citizen has a good backgrounder on where things stand now with this desire to trade people as services, yet, will this change?

Here are some recently press reports, most notably India, demanding to trade people via guest worker Visas be included in the next round of trade talks.

Where Countries Stand on Doha trade talks reports on India and China's guest worker Visa demands:

- Some developing countries like India and China have a big interest in seeing progress in one area of services -- liberalisation of the movement of labour for people to travel to fulfill contracts, known as "Mode 4".
- India also wants a discussion of services at the Easter (WTO) meeting because of its big IT, business process and outsourcing sectors

From IndiaTimes, India Tells WTO Don't Push for Premature Trade deal:

The country is looking forward to easing of restrictions in the temporary movement of workers and professionals (mode 4) to other countries and securing business flow in the outsourcing segment (mode 1) in the services negotiations.
India said the stand taken by some that the services negotiations concern a sub-set of members and that such members should seek assurance from each other was not the way India looked at the negotiations

From Industry Standard (India)

The US said it wanted value-addition in the services text by including clear language about binding current market access commitments in square brackets, while Brazil said the US must discuss with its Congress whether it is ready to address the issue of Mode 4 concerning the short-term movement of services professionals, arguing that the level of ambition in services must be on par with what is being done in agriculture

A threat to not cut farm tariffs, India's demands to trade people for farm duty cuts:

India wants to know what it is going to get in the movement of short-term services providers under Mode 4 and removal of restrictions on cross-border services.
Up until now, the US maintained that it could not provide much access in these two areas because of opposition from its domestic constituencies.
“We, therefore, urge you to propose a structured discussion to address this need,” India’s trade envoy said

And it's not just jobs they are trading, look at the globalization agenda of higher education, Global U:

The World Trade Organization has been pushing trade-services liberalization for several years, of which higher-educational services are a highly prized component, with an estimated global market of between $40 billion and $50 billion (not much less than the market for financial services)

So, the educational "market" is 2.5 trillion and rivals the financial services market. Great our US taxpayer dollars are going to help universities turn into for profit business entities where the student is now the product.

What does this mean? It means that the WTO has pressure and an agenda to supercede US domestic immigration and guest worker Visa policy, claiming trading people are simply services to be traded and that means global labor arbitrage

Think it's about immigration, moving to a new country, adopting it as one's one? Think again.

AFSC page listing all of the problems with GATS mode 4 and this article calls it what it is, Legalized Human Trafficking.