In module 5 on population growth we discussed two different phenomena. In answering\ this question, explain each in your own words.\ a) (3) Why are national-level population growth rate decreases correlated with national-level\ average income increases? Hint: this correlation is part of what is known as the demographic\ transition.\ b) (3) At a given level of national-level average income, unexpected increases in number of\ children (for example, twin births) do not appear to cause decreases in the average amount of\ household resources invested per child. Why? Hint: this is the subject of Chapter 5 of Banerjee-\ Duflo