Backers of a common market however should think very long and hard about this idea. Why is that? Three reasons: First. a common market like the European Community has totally free movement of labor. What does that mean? That means a Spanish citizen. for example. in Madrid can get on a train. go to Paris. London. anywhere in the Common Market. find work on a visa. without a permit. no hindrances. no restrictions. get off the train. walk to the plant. and apply. I do not think that we Americans would like that to apply in this continent now. In addition. the European Common Market has coordinated tax and health policies.