A thought about inequality and growth

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The distribution of income and wealth in the United States has become more and more unequal. Wikipedia summarizes a 2007 study:

(I)n terms of relative mobility it stated: "contrary to American beliefs about equality of opportunity, a child’s economic position is heavily influenced by that of his or her parents." 42% of children born to parents in the bottom fifth of the income distribution ("quintile") remain in the bottom, while 39% born to parents in the top fifth remain at the top. Only half of the generation studied exceeded their parents economic standing by moving up one or more quintiles. Although one third of the nation is moving up quintiles, another third is downwardly mobile — experiencing a decrease in income and economic standing compared to their parents. Moving between quintiles is more frequent in the middle quintiles (2-4) than in the lowest and highest quintiles. Of those in one of the quintiles 2-4 in 1996, approximately 35% stayed in the same quintile; and approximately 22% went up one quintile or down one quintile (moves of more than one quintile are rarer). However, 42% of children born in the bottom quintile are most likely to stay there, and another 42% move up to the second and middle quintile. On the opposite end of the spectrum, 39% of those who were born into the top quintile as children in 1968 are likely to stay there, and 23% end up in the fourth quintile. Children previously from lower-income families had only a 1% chance of having an income that ranks in the top 5%. On the other hand, the children of wealthy families have a 22% chance of reaching the top 5%.

Does the inequality and limited mobility relate to the rate of growth of the U.S. economy? I suspect that it might. If, as I believe, economic growth means creative destruction, then people would have to change their jobs and their economic roles frequently; would not diminished economic mobility suggest that there are factors in the economic institutions that militate against rapid changing of economic roles?

Moreover, the creation of new firms and especially the creation of new disruptive innovations has been a vehicle for people to become rich. If fewer people are making that transition, and if the already rich are more successful in maintaining their relative economic advantage, does it not suggest less innovation to drive growth?