Ünite Sınavı Soruları

I. It is a common issue in statistical and econometric analysis that arises when the explanatory variable(s) used in a regression model are correlated with the error term or disturbance in the model. 

II.  The correlation between the explanatory variable(s) used in a regression model and the error term or disturbance violates the assumption of exogeneity, which is a key assumption for obtaining unbiased and consistent parameter estimates in regression analysis.

III. In simple terms, endogeneity bias occurs when there is a one-way causal relationship between the independent variable and one or more regressors, making it difficult to determine the true cause-and-effect relationship.

What can be said to be true about the endogeneity bias?

What is a endogenous regressors?

I. Supply and Demand Equations

II. Economic Profit Equation

III. IS-LM Model

IV. Investment and Savings Equations

Which of the given equations in economics can be listed as simultaneous equations?

What is the situation where one or more variables used in a statistical analysis are measured imprecisely or with error?

Which two conditions should a proper instrument should satisfy?

I. Endogeneity problem in regression models occurs when the Gauss-Markov assumption on zero
the conditional expectation is violated. 

II. The endogeneity problem (bias) results from the independence between the model’s error term and regressor(s).

III. The error term is independent of the regressor if this assumption fails, we cannot control other variables since the error term and regressor move together.

What can be said to be true about the Endogeneity problem?

I. A simultaneous equation, also known as a system of equations, is a set of two or more equations with multiple variables that are connected and must be solved together.

II.  The solution to a simultaneous equation is a set of values for the variables that satisfy all the given equations simultaneously. 

III. In economics, simultaneous equations are rarely used to model various economic relationships and phenomena.

Which of the given statements can be said to be true about simultaneous equations?

Which of the given statements about the reasons to test for endogeneity can be said to be false?

I. The 2SLS method addresses the endogeneity problem by using instrumental variables (IVs) to proxy for the endogenous variables and identify the causal effect more accurately.

II. The 2SLS method is unusable when dealing with simultaneous equations models where there is endogeneity and simultaneous causation between variables.

III. The two-stage least squares method is an essential tool in econometrics for addressing endogeneity and obtaining reliable estimates of causal relationships. 

What can be said to be true about the Two-Stage Least Squares method (2SLS)?

I. The main idea in testing overidentification restriction is to check whether any instrument is endogenous.

II. “Exogeneity” of the instruments dictates that the instruments should be related to the error term of the original regression

III. The test done to testing overidentification restriction can tell us which instrument(s) is(are) problematic.

Which of the given statements about "testing overidentification restrictions" can be said to be true?