Questions tagged [omitted-variable-bias]
The omitted-variable-bias tag has no usage guidance.
16
questions with no upvoted or accepted answers
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Question about statement in Oster (2019): variation in a control
In Oster (2019), she discusses how authors typically include controls and examine coefficient stability as a way to test for presence of confounding, and points out that researchers should consider ...
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How to test whether OVB by examining two regressors (X_1, X_2) using hypothesis test with null hypothesis H0: corr(X_1,X_2) = 0
Suppose you have an i.i.d. sample ${(π_i , π_{1,i} , π_{2,i} ): π = 1, ... , π}$. You want to estimate the causal effect
of $π_1$ on $π$. You first run a regression $π_i = πΌ_0 + πΌ_1π_{1,i} +...
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Derivation of Neuhaus, Jewell(1993)
I wish to ask a derivation problem in Neuhaus, Jewell(1993) - "A geometric approach to assess bias due to omitted covariates in generalized linear models"
The statistical True model dealt in ...
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Using an IV when there is more than one omitted variable
I am trying to estimate the following model:
$$y=B_0 + B_1x_1 + B_2x_2 + B_3x_3 + e$$
However, I have an omitted variable bias because $x_2$ and $x_3$ are not observed.
Situation 1
If I have an (...
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Can an omitted random variable cause "omitted variable bias"?
Suppose we have a linear regression:
Y = mx + b
where X is the independent variable of interest, in this case "scoops of ice cream per order" at an ice cream shop, b is the error term, and Y is the ...
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1
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1
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70
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Comparing IV and OLS results to get infomation about the omitted variable correlation
Very often in seminars people compare the (biased because of endogeneity) results of their OLS estimation with those (unbiased) from an IV strategy estimation. Assuming everything is ok with the IV ...
1
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control "for post-treatment" variables vs omitted variable bias
in chapter 9 of gelman's data analysis using regression and multilevel/hierarchical models, page 170 presents a simple example on the bias of an omitted variable $x$ from a regression of an outcome $y$...
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Does omitted variable bias affects coefficients for those variables that are not correlated with the error term? (When their is one variable that is)
Does omitted variable bias affects coefficients for those variables that are not correlated with the error term? (When there is one variable that is.) I found two answers, but they appear to be ...
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Do insignificant variables result in a specification error?
I am trying to understand omitted variable bais better. I know that it detects irrelevant variables, but are irrelevant variables and insignificant variables synonymous here? If I have a regression ...
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Instrument validity: does a positive and significant coefficient on Z in a regression of Y on X and Z pose a problem?
I have an initial regression of Y on X and Z. Both of my coefficients on X and Z are non-zero and strongly statistically significant. X and Z are correlated but I am told collinearity shouldn't be an ...
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Can I use DiD for a RDD design? (treatment determined by threshold)
is it possible to apply a Difference-in-Differences method for a quasi-experiment that determines treatment by a threshold? All schools below a certain API rank are treated the rest is not (control). ...
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132
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Omitted Variables Bias and time-invariant variables
In empirical research, when working with panel data sets, it is common to include time fixed effects (e.g., year dummies) into your regression model to account for unobserved heterogeneity across time,...
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Variance of linear regression model with omitted variable bias
Suppose we have the following data generation process:
\begin{align*}
U &= N_{U}\\
X_{1} &= \alpha_{1}U + N_{1}\\
X_{2} &= \alpha_{2}U + N_{2}\\
X_{3} &= \alpha_{3}U + ...
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VAR model variable selection
I'm required to use two time series models in my exam project.
I want to use a stock price of an energy company, and then explain it first using ARIMA, and then adding other variables and using VAR.
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Question about regression and deriving omitted variables
usually when I see derivations of ommited variable bias, I see something of the sort:
from y=xb + $\eta$, and looking at the for formula for the slope estimate:
$cov(x,y)$$/var(x)$
$cov(x,xb+\eta )$$/...
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Are coefficients that are zero omitted variable bias?
If a regression coefficient is essentially zero, doesn't that imply that there is (massive) omitted variable bias? That is, the change must then exist in the error term.
The classic definition of OVB ...
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