1.) Revealed preference refers to

a. preferences that we understand through careful theoretical models regarding preference formation.

b. preferences that we understand because we have presented people hypothetical scenarios to elicit their preferences.

c. preferences that we understand because of intentional interactions with behavioral psychologists.

d. preferences that we understand as a result of observing people's behavior in market.

2.) Suppose that a researcher decides to value a view of the Willamette valley by comparing the price of houses at on Vineyard Mountain with the price of houses near the downtown library.Which of the variables below might be an important omitted variable in this comparison?

a. the soil quality in both sites.

b. the education levels of the house owners.

c. the square footage of the houses.

3.) Suppose that a researcher compares the income of farmers relative to teachers in a effort to establish a "price" for the risk inherent in operating farm machinery.The fact that it may well be the case that people who choose to become farmers have a higher tolerance for risk introduces the problem of ______________________ into this comparison.

a. selection bias

b. measurement error

c. omitted variable bias

4.) A recent paper in environmental economics uses data from Alibaba purchases of face masks from people living in Beijing to estimate their willingness to pay for reduced air pollution.This method is an example of:

a. the travel cost method.

b. the asset valuation method.

c. the defensive expenditures method.

d. the hedonic pricing method.