Why the US economy is becoming less dynamic

US companies still make an effort to modernise their capital and spend heavily on R&D, and the new technology sector is large in the United States. Yet labour productivity and total factor productivity are slowing down. A n abundant and converging research literature (see Appendix) explain s the US economy’s loss of dynamism as follows: Corporate concentration has increased, hence the rise in profit margins and the skewing of income distribution at the expense of employees; The proportion of new companies has fallen, and so has their weight in the US economy; Dominant companies use innovation to protect themselves, and therefore do not transfer innovation to other companies: the efficiency gap between the most productive and the least productive companies is widening. So it seems that the loss of dynamism in the US economy is due to effects of the appearance of dominant companies that limit the dissemination of innovations in order to protect themselves.