What factors might contribute to a low level of productivity in an economy?

I can't say I know much about the productivity growth of the US in the 1990s but it may help to compare the US experience during the 90s to the following reasons for low productivity in an economy (as the US likely experienced improvement in these fields). An economy is likely to have low levels of productivity if: Worker education is poor/short in duration Levels of technology are low Numbers of workers are too small or too large (too large being explained by "too many cooks spoil the broth", that is- diminishing returns to labour) Those are probably some of the main factors, others include: The speed or difficulty of setting up a business being high. Poor infrastructure (roads, telecoms etc) meaning that communication and transport is slow/difficult If you are looking at agriculture based economies then factors such as an arid climate or poor soil will mean productivity (of growing crops) is low There are many arguments that productivity is lower in Centrally Planned Economies (effectively communist economies) although these are rare today (examples today include North Korea and Cuba to an extent), the most famous example being China. Productivity is likely to be low as there are low or no incentives to improve productivity. Hope this helps!

lack of education, weak property laws, anti-business government or population