The effects depend on the sector. It also depends on who is being effected. In the short term, if a sector moves oversees then the people who are trained to work in that sector are out of work. They cannot move with their jobs, because their jobs went to less skilled, lower-paid workers in another country. Thus, if you are the person whose job was outsourced, you probably do not feel that international trade is a good thing. On the other hand, if your company makes something that it sells to other countries, trade is a good thing for you.
If we are able to be involved in exporting products it should be able to provide more jobs for our country. If we are importing more goods than we are exporting then we are likely loosing jobs.
I think it does depend on which way that trade is moving. We conduct a massive amount of international trade, but with an annual trade deficit that is staggering. I don't think our over dependence on foreign oil or the outsourcing of most of our manufacturing base has had a positive effect on our employment or economic growth. Sure, products are cheaper, but they need to be, because the gap between rich and poor has grown considerably in the last thirty years.
According to economists, the long term effects of international trade are all positive.
Economists say that trade will lead to each country producing things in which it has a comparative advantage. When all countries specialize in this way and then trade with each other, the world as a whole will be able to make and consume more products than it could without trade. This, clearly, would cause an increase in employment and in economic growth.