if you look at history you will get to know why economy is strong as usa is located far from europe and asia it was not part of second world war so as all other countries suffer from ar they were out and safe so they can improve on what was built all in other world started from scratch.....if you see statistics 70% of american institutes not look for merit but they take people from other countries for fees not for merit ......so most of people who dont get admission here and have money study there...