You Have Learned in One of Your Economics Courses That $$\widehat { \text { RelPersInc } } = 0.518 - 18.831 \times \left( n - n _ { u s } \right) , R ^ { 2 } = 0.522 , S E R = 0.197$$

You have learned in one of your economics courses that one of the determinants of per
capita income (the "Wealth of Nations")is the population growth rate.Furthermore you
also found out that the Penn World Tables contain income and population data for 104
countries of the world.To test this theory, you regress the GDP per worker (relative to
the United States)in 1990 (RelPersInc)on the difference between the average population
growth rate of that country (n)to the U.S.average population growth rate (nus )for the
years 1980 to 1990.This results in the following regression output: $$\widehat { \text { RelPersInc } } = 0.518 - 18.831 \times \left( n - n _ { u s } \right) , R ^ { 2 } = 0.522 , S E R = 0.197$$ (a)Interpret the results carefully.Is this relationship economically important?