Questions tagged [instrumental-variable]
The instrumental-variable tag has no usage guidance.
28
questions
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Why are my 2SLS estimates much larger than my OLS estimates?
When performing IV regression, it is often taken as a sign of unbiasedness if the IV estimates are similar to the OLS estimates of the same model. My question is: If the estimates are very different,...
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0answers
26 views
Weak Instrument - Stock and Yogo
I have the following structural equations where $G,Z$ are endogenous and $X,Y$ are exogenous
$$ G_d=B_0+B_1Z+B_2X+u_1\\
G_s=a_0 +a_1Z+a_2Y+u_2 \\
G_d=G_s
$$
Now, I would like to perform 2SLS, thus, ...
3
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2answers
85 views
Some confusions about instrumental variable (econometrics)
As the title says, I have some confusions about instrumental variable.
According to my lecture note (which is supposed to be reliable), instrumental variable has two big properties:
Validity: an ...
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18 views
Over What Ranges Can Elasticity Estimates Be Applied
I am reading the following paper: https://onlinelibrary.wiley.com/doi/full/10.1111/1756-2171.12113
The paper attempts to estimate the elasticity of pharmaceutical innovation (measured by # of new ...
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13 views
Testing for endogeneity when the model does not have any known exogenous variables?
so I was wondering how can one test for endogeneity in a model if the model does not have any known exogenous variables, there are no instruments available for the suspected endogenous variables? I ...
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1answer
20 views
Is it reasonable, in panel data, to use past values of explanatory variables as instruments to deal with simultaneous causality?
I am trying to examine the determinants of economic growth, essentially regressing a number of variables upon economic growth. I face a problem that there is likely simultaneous causality between many ...
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14 views
Correction of standard errors in IV model
In reference to paper titled "Estimation with Many Instrumental Variables" by Hansen, Hausman and Newey, I wanted to know how to find corrected standard errors in Stata for the many instruments case.
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1answer
27 views
Testing for weak instrument
I have 3 endogenous variables in my model and I have identified 3 (or max 4) instruments. I wanted to know appropriate test for identifying whether the instruments are weak or not given that I have ...
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29 views
instrumental variables
I have a question related to IV methods. Suppose I have a regression
$Y = a + b_1 X_1 + b_2 X_2 + \epsilon$,
where $Y$ is a dependent variable and $X_1$ is an endogenous independent variable and $...
3
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1answer
51 views
Imbens and Angrist (1994): the $D_i(z)$ variables
I'm referring to the Econometrica (1994) paper by Imbens and Angrist. In particular, I don't really understand the random variables $D_i(z)$ (defined on page 468). Could you please provide me with ...
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1answer
48 views
Validity condition for Instrumental Variables
My professor states the validity condition in the following way:
$W$ (the matrix of instrumental variables) must be such that
$ \text{plim} \, \frac{W'u}{N}=0$, where $u$ is the error term.
...
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1answer
575 views
Confounding versus endogenous variables. What is their relative hierarchical position?
There are valuable resources on the lexicon of types of variables quickly accessible, such as here. However, some of these concepts appear side-by-side often enough to make them confusing.
For ...
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2answers
146 views
Instrumental Variable Paper for Minimum Wage
I am trying to write a paper dealing with minimum wages and employment. I understand there is simultaneity bias between these two variables so I must come up with an instrument. Does anyone have any ...
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0answers
35 views
Using an instrument in IV that is not strictly exogenous to the variable it is instrumenting?
I am considering instrumenting HIV with ODA, to evaluate the impact of HIV on gold mining. There is a clear relationship between HIV and ODA, however it may easily be argued this is an endogenous ...
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1answer
63 views
Difference between $x$ and $X$
Sorry for my bad english, i'll try to explain my difficulty.
1° Question
In the last exam an exercise asked to derivate OLS estimators and calculate their value with the data provided (ex.: $\sum ...
2
votes
2answers
407 views
Testing for Endogeneity
I apologize if this question is very basic. I have the following plain vanilla Instrumental Variable model.
$Y=\alpha+X\beta+\varepsilon$
$X=\delta+Z\gamma+\eta$
$\varepsilon\perp\eta,\quad Z\perp\...
4
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1answer
1k views
Can you use more than one instrumental variables in an Econometric model?
Can you use two instrumental variables $z_1$ and $z_2$ at the same time for $x_1$ and $x_2$, in the following regression model
$y=a+bx_1+cx_2+dX_{other}+e$, where
$y$ is the explained variable,
$...
4
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1answer
85 views
Testing if one regressor is a proxy for another
I'm reading Guiso, Sapienza and Zingales: "Trusting the Stock Market" The Journal of Finance, Vol. 63, No. 6, 2008 and have a question about how they test whether trust is a proxy for risk aversion.
...
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343 views
How to test if variables are jointly determined?
If I wanted to test, for example, if consumption growth and credit growth are jointly determined, and therefore justifying the use of instrumental variables, how would I go about this? Would running a ...
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votes
3answers
13k views
What is the difference between two stage least squares and instrumental variable regression?
I'm doing independent study and I am having trouble understanding the difference between these two estimators.
I get that 2SLS is predicting the endogenous variable, and that instrumental variables ...
0
votes
1answer
396 views
IV：Quasi-random variance V.S. 'Placebo' check
I read some papers about transportation infrastructure. I am confuse with the following two case.
Some routes are unlikely to have been randomly assigned across cities over time. Thus, In some papers(...
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0answers
61 views
Trouble Deriving Indentification Scheme in Gertler-Karadi (2015) AEJ
I'm having trouble following a derivation that Gertler-Karadi (2015) AEJ http://pubs.aeaweb.org/doi/pdfplus/10.1257/mac.20130329 do in their paper on Footnote 4 on the bottom of page 52. I've tried ...
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2answers
145 views
Using another person's guess as an IV
In Estimates of the Economic Return to Schooling from a New Sample of Twins by Orley Ashenfelter and Alan Krueger, they correct sampling error with an IV. They claim that their results imply a larger ...
3
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2answers
636 views
How to justify an instrumental variable?
I am hoping for some tips on what I could do for a term paper in applied econometrics. We are running a 2sls where I want to use a firm's location as an IV. How can I go about justifying it is a valid ...
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1answer
366 views
Which regression technique is used for calculating price elasticity in practice
Since we need to consider 'Endogeneity' between price and quantity while calculating price elasticity and since linear regression cannot handle the phenomenon of endogeneity if objective of the model ...
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122 views
Using an interaction term as the instrument (as in Barro QJE (2011))
I recently came across Barro and Redlick QJE (2011) paper, "Macroeconomic Effects from Government Purchases and Taxes", in which the authors instrument for defense spending with an interaction term ...
7
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2answers
840 views
Best instruments for “years of schooling”/“education”
As an answer to question “Seminal papers that later were proven to contain errors”, @snoram mentioned Angrist and Krueger (1991), and there use of quarter of birth as an (exogenous) instrument for ...
5
votes
1answer
165 views
IV - Is this procedure valid?
I have three variables: $y$, $x_1$ and $z$.
I'm interested in finding the effect of $x_1$ on $y$.
Unfortunately $x_1$ is endogenous so I use an instrument z.
I know that $z$ is correlated with $x_1$....
