An observational study provides a biased estimate of the true effect of a treatment on a medical outcome because:

a. it is difficult to find a control group that is equivalent to the treatment group.
b. the treatment and control groups are randomly selected.
c. the treatment group and the control group are too similar.
d. no one wants to serve as a guinea pig for randomized trials.
e. everyone wants to be in the treatment group


a. it is difficult to find a control group that is equivalent to the treatment group.

Economics

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Economics

New classical economists

a. accept the monetarist notion that markets are perfectly competitive except for a lack of perfect information. b. do accept the difference between the short-run and long-run results in the monetarist analysis of the effects of aggregate demand on output and employment. c. accept the difference between the short-run and long- run results in the Keynesian analysis of the effects of aggregate demand on output and employment, but not in the monetarist analysis. d. accept the difference between the short-run and long-run results in the monetarist analysis of the effects of aggregate demand on output and employment, but not in the Keynesian analysis. e. Both a and b

Economics

Suppose that the absolute price elasticity of demand for hamburger is 1.15 and that the absolute price elasticity of demand for steak is 2.4. Then the absolute price elasticity of demand for beef will be

A) less than 1.15. B) more than 2.4. C) between 1.15 and 2.4. D) equal to 1.15.

Economics

To make rational forecasts, your predictions do not have to be correct all of the time

a. True b. False Indicate whether the statement is true or false

Economics