Final answer:
GDP is used by economists as a measure of a country's economic health, and GDP per capita is closely linked to productivity. High corruption levels are correlated with lower GDP per capita, and long-term growth in GDP per capita requires an increase in worker productivity or capital.
Step-by-step explanation:
Economists use gross domestic product (GDP), or the total value of goods and services produced, to measure a country's economic health. The correlation between a nation's GDP per capita and productivity levels indicates the average wealth and performance of its economy. Furthermore, the presence of corruption in a country has been found to affect its productivity negatively, as higher corruption levels are correlated to lower GDP per capita. It is also crucial to note that GDP per capita growth can be sustained over the long term only if there is an increase in the productivity of the average worker or if this is supported by increases in capital investments.