Why is it often not possible to establish a temporal relationship between exposure and disease with a cross sectional study?

Imagine a child who consistently gets mediocre grades and is often picked last for a team when games are played at recess. however, he likes to make silly jokes and play pranks, and he notices that people laugh when he does those things. the child starts to think that others are laughing with him, not at him. this is part of the process that charles cooley

Mankiw attributes – chapter 1 and his 10 principles – differences in living standards within a countryover time and across countries at a moment in time to: a. the presence or absence of inflation and unemployment. b. the allocation of resources between private markets and the public sector. c. those that have dealt successfully with the efficiency v. equality tradeoff and those that haven’t. d. differences in productivity. e. ones that think at the margin and respond to incentives and those that don’t.

The bill of rights includes things such as the right to bear arms and freedom of speech. these are examples of which american value?