Good things about globalization:
1. International trade keeps prices low and quality high. Anytime a country in the past has tried to be self-sufficient and not partake in the global markets, they find that their businesses become inefficient due to a lack of competition, prices rise, their products lack innovation, and they end up with hyperinflation.
2. Globalization can bring wealth to some of the world's poor. For example, much of Southeast Asia was terribly poor a few decades ago; thanks to globalization and international trade many of these countries have experienced annual growth in the double digits and many of those people are now much better off than their parents were a generation ago.
3. Globalization can help bring world peace. As every country on the planet becomes more interconnected with every other country, there is a serious incentive for all of the involved to keep the peace. Thomas Friedman, in his book "The Lexus and the Olive Tree", goes so far as to discuss the "Golden Arches" theory of world peace--he says that no countries that have McDonald's have ever or will ever attack each other.
4. Globalization could help protect the environment. Some people have pointed out that in the past a nation like China could have produced as much pollution as they would have like to, but today if China wants to engage in the global marketplace the rest of their trading partners could potentially put pressure on them to clean up their act.
The bad things:
1. Globalization has led to greater disparity in wealth within many countries. Back to Southeast Asia, the people of those countries did experience a tremendous amount of growth over the past couple of decades, but it wasn't experienced equally by all of their people. The poor have seen a moderate rise in incomes while the wealthy have seen incredible rises in their incomes.
2. The creation of what is essentially a single large global market entails certain