Threats to in internal validity lead to
A. perfect multicollinearity
B. the inability to transfer data sets into your statistical package
C. failures of one or more of the least squares assumptions
D. a false generalization to the population of interest
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The true causal effect might not be the same in the population studied and the population of interest because
A. of differences in characteristics of the population
B. of geographical differences
C. the study is out of date
D. all of the above
Consider the following regression model: log(y) = β0 + β1x1 + β2x12 + β3x3 + u. This model will suffer from functional form misspecification if _____.
A. β0 is omitted from the model
B. u is heteroskedastic
C. x12 is omitted from the model
D. x3 is a binary variable
A regression model suffers from functional form misspecification if _____.
A. a key variable is binary.
B. the dependent variable is binary.
C. an interaction term is omitted.
D. the coefficient of a key variable is zero.
Which of the following is true?
A functional form misspecification can occur if the level of a variable is used when the logarithm is more appropriate.
B. A functional form misspecification occurs only if a key variable is uncorrelated with the error term. .
C. A functional form misspecification does not lead to biasedness in the ordinary least squares estimators.
D. A functional form misspecification does not lead to inconsistency in the ordinary least squares estimators.