Define, using your own words, the following concepts. a. Instrumental variable
b. Exclusion restriction
c. Conditional mean independence
d. Parallel trends (in the context of Difference in Differences)
e. Fixed effects.

Nikolas works in a shoe store as a salesperson. a teenage boy comes in looking for comfortable sports shoes because he is going on a hike. he tells nikolas he wants shoes that have velcro straps. nikolas shows him a wide variety of velcro-strapped shoes, but the customer rejects them because they don't feel comfortable. he asks for sports shoes with laces instead. nikolas once again shows him a wide variety. the boy is once again not satisfied and asks to see the velcro-strapped shoes again. nikolas is irritated but doesn't show his annoyance. what customer service skill is nikolas showing? nikolas is a. meekness b. patience c. persistence

%of the world's population controls approximately % of the world's finances (the sum of gross domestic products)" quizlket

Mark knopf is an auditor who has been asked to provide an audit and financial statement certification for a company that is going public on the new york stock exchange. knopf wants to know his personal liability if the company provides him with inaccurate or false information. which of the following sources of law will him answer that question? a. the city ordinances where the company headquarters is located. b. the state constitution of the state where the company is incorporated. c. code of federal regulations. d. all of the above