But does economic integration really need to imply economic uniformity? I do not think so. This can clearly be seen in the United States. Regional economies are hit by different economic shocks and perform differently owing to their differing economic structures, even over extended periods.
For example, reported levels of life satisfaction among Americans are similar to reported levels among Costa Ricans, who have about one-quarter the per capita income. 6 So I am going to continue under the assumption that, although wealth and income do contribute to happiness and life satisfaction, other factors must also be very important.