Lets take a look more closely at the American Higher Education system as it stands today. For better or worse, this is the model all other countries look at, to improve their performance in science and engineering research output. American academic culture is very different then European and other models I have seen in my life (I have worked in Israel, Germany, and in IISc, India before coming to USA) and One needs time to adjust in the academic culture of America. I hope some idea about it probably will be more helpful for the people who are planning to go for post-doc or Ph. D. programs in USA and make them prepare better for academic life in America.
For more detail information on the American academia in STEM fields (Science, Technology, Engineering and Mathematics), please refer to a well written book "Tomorrow's Professor: Preparing For Career In Science And Engineering" by Richard M. Reis. This book is a must read for anyone who is thinking of academic career in USA. As a complimentary book, one can also read "A Ph. D. Is Not Enough" by Peter J. Feibelman. Together they give good enough picture of American academia in STEM.
The classification of higher education institutes in USA is done on the basis of their priority on teaching or research. The institutes are classified in four categories (For more detailed information, please visit the site "http://www.carnegiefoundation.org/index.asp" ):
1. Research Universities (also called R1 Universities): These are the top ranking universities with major focus on the research. Although they offer bachelors programs in many disciplines, but Research and publications are their main priorities and teaching takes a back seat in these institutes. Since the priorities of these institutes is research, and also the source of their funding, they encourage fierce competition for the research funding and publications. The top tier research institutes in USA run on corporate model. In many cases, faculty has to earn part of their salary through federal funding. Typically students and post-doc work long hours and weekends as well. The period for promotion from Assistant Professor to Associate professor is 6 years which they recognized as the granting of tenure. The requirements for getting tenure in these institutes is typically 5-10 publications and funding from external source. Once the tenure is granted, the faculty becomes permanent in the university.
2. Doctoral Universities: These institutes offers bachelors programs and doctoral programs in many disciplines and the focus is combination of teaching and research. Life is more easy at these institutes and one can combine teaching and research nicely. The money (salary, funding etc etc) is smaller at these places as compare to R1 universities.
3. Master's College and Universities: Mostly undergraduate colleges with masters programs in few disciplines: completely focused on teaching. Faculty is focused on teaching with some research expectations during the summer. Research funding in these institutes is mostly of educational nature to promote science education in the students.
4. Liberal Arts college: Mostly undergraduate colleges. Also completely focused on teaching. research and teaching expectations are same like Master's colleges and universities. Life is at easy pace in these institutes as well.
What is good in this model is that the expectations and consequences are clear for each type of institutes and one can choose which institutes suits one's need better and accordingly try to work out the solution. I have seen people choosing to go to college teaching after getting Ph. D. from top ranking R1 university with excellent publications because they don't like the pace of life and competition in the top tier university. At the same time there are people who after spending time in college teaching involves in research and finally ends up at research university because they want more challenges. It may not be easy to go from teaching based institutes to research based institutes, but is entirely possible if one is determined. This freedom to move from one place to another, as one matures and as interests and priorities of life changes, is the best package of American academia and life.