Today the poor countries of the world do not have much higher output per capita or levels of living than they had two hundred years ago while the industrialized countries have levels many times greater than the poor countries today or than these same countries had before about 1800. These differences are clearly not due to differences in access to natural resources. Note the number of countries with high GDP per capita that have less than average per capita natural resources. The source of much of the increase in output pre capita over time must be from the potential capacity created by the accumulated knowledge. But the existence of knowledge alone cannot explain the persistent differences in output among economies since knowledge has become highly portable.
Much knowledge is embedded in technology which is tradable.
Much knowledge is available in a written form with little restriction in its availability. And, much knowledge is held by individuals who would be willing to transfer that knowledge to other economies in market transactions or even to provide it as a gift. The most important factor missing from the economies of the poor countries is the set of institutions creating economic systems with the structure of incentives and opportunities which promotes the acquisition and use of the accumulated knowledge of the world to improve levels of living. This is not to suggest that instituting an economy to create the organizations and individual incentives leading to high levels of output is easy or can be done very quickly. Modern production requires complex and highly coordinated activity.