Questions tagged [selection-bias]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
0
votes
0answers
20 views

Heckman Selection (Selection vs. Outcome equation)

A common example of the Heckman selection model involves wages, which are only observed if an individual chooses to participate in the labor force. The first stage probit model dependent variable is a ...
1
vote
2answers
35 views

How to solve selection bias in a survey?

Selection bias often happens in survey studies. For example, sending out a survey to 10,000 customers to ask whether they like one specific product or not. Only 10% of people respond and 80% of them ...
1
vote
0answers
62 views

Heckman with second step probit in R

The functions selection and heckit (package sampleSelection) support a binary dependent ...
1
vote
0answers
15 views

Selection bias in categorical independent variable in regression analysis

I have an issue with selection bias in my independent variable and I am uncertain of the best approach to correct for it. I'm looking at soccer data and trying to make some forecasts on players from ...
0
votes
0answers
9 views

Should I use a Heckman Selection Model when extracting a subset of my data for analysis?

I am new to heckman selection, and am having trouble applying it to my case. In fact, it's possible I should not be using a selection model at all, so I wanted to check first. My dependent variable ...
0
votes
1answer
20 views

Alternatives to balance tables to examine selection bias

I was wondering if someone has ideas to statistically examine selection into programme participation? For example, would it make sense to present the results of a propensity score analysis? Thank you
1
vote
0answers
14 views

Correcting for known imputation bias

I have a survey sample which includes income values by type of income for a significant number of high-income households. Some of the income data is measured, i.e. present in the responses of the ...
0
votes
1answer
60 views

Sample Selection Bias in Logistic Regression [duplicate]

I'm working on a classification problem where I expect $True\ Positive\ Rate =0.999$ $True\ Negative\ Rate = 0.001$ To model this data, I have created a training set with an equal proportion of ...
0
votes
0answers
7 views

How to estimate an activity based on self reported activity in a social network

I help run a social network for rock climbers who self report what they have climbed on a specific day, and optionally who they climbed it with. These climbers who self report are a perfect lower ...
5
votes
2answers
56 views

Favored methods for overcoming selection bias (special attention to healthcare fields)?

I am frequently measuring the effect of behavioral health treatment interventions on outcomes of interest. However, comparing the relative efficacy of different types of treatment is tricky - more ...
0
votes
0answers
31 views

How to correct for selection bias in a situation where usual Heckman correction won't do? Should I even do it?

I have a question about how to correct for selection bias in an experience. In this experience, we evaluate the impact of slight tweaks in phrasing on web surveys participation. For example, if you ...
0
votes
1answer
40 views

What is the correct notation for expressing a mixture of distributions?

In a normal classification context, the training instances are drawn from a distribution $D$ which is defined over $X \times Y$, where $X$ is the feature space and $Y$ is the label space. When ...
0
votes
1answer
49 views

Sample selection bias

In Learning and Evaluating Classifiers under Sample Selection Bias, we suppose that examples $(x, y, s)$ are drawn independently from a distribution $D$ with domain $X × Y × S$ where $X$ is the ...
0
votes
0answers
112 views

How to perform inference on inverse Mills ratio in Heckit estimation?

I want to estimate log(wages). Most wage estimations suffer from sample selection bias. So I used the two step heckit procedure to correct for it. The problem is that I get an insignificant inverse ...
1
vote
0answers
53 views

Can selection bias be solved by including control variables?

Omitted variable bias can be solved by including covariates that are omitted. However, can selection bias also be solved by including covariates?
0
votes
0answers
20 views

Logistic regression when only TRUE values are observed, but a control sample exists

I'm involved with a creel survey. We have reason to believe that anglers are keeping the larger fish they catch, or at least that a relationship exists between the size of caught fish and the ...
0
votes
1answer
130 views

Correcting sample selection bias of binary classifiers

In fraud investigation the number of detected fraud cases can be very small when compared to the total number of cases. This would also apply to rare desease detected in a very small number of people ...
0
votes
1answer
251 views

IV-estimation vs. Heckman's selection model

I am trying to grasp the difference between IV-estimation and Heckman's selection model. I do that by considering the following set-up. My outcome if interest is y ...
2
votes
1answer
542 views

Why does weighted bootstrap have awful coverage even in toy example?

I'm interested in using the weighted bootstrap to correct for selection bias with a known form. I simulated a very simple example where the underlying data, $X$, are $N(0,1)$ and we are calculating a ...
5
votes
2answers
204 views

Is this actually an example of selection bias?

In Lesson 3, Chapter 3 of Miguel Hernán's edX course on causal diagrams, he presents this DAG: It represents a study on the effect of hormone therapy on lung cancer (whether hormone therapy causes ...
3
votes
2answers
227 views

Usage of Heckman estimation for a random sample

My colleague argues to use a Heckman Model in the following case (Agricultural economics): I have a random sample of farmers (n) of the general population N. In n some observations apply a given ...
2
votes
1answer
154 views

In what instances do we need to worry about Heckman correction for selection bias?

I understand that Heckman selection models attempt to address selection bias by running two-part models. In the oft cited example of determinants of wage offers: 1) we have a group of people who work ...
1
vote
0answers
69 views

How to handle bias due to self-selection in one group

I want to compare two or three social groups across a set of dependent variables, using data from a longitudinal survey. The problem is that membership in one of the groups leads to a self-selection ...
4
votes
0answers
226 views

Correcting Sample Selection Bias given actual Distribution

I have two datasets, both from the same population: The samples from the first survey are quite representative of the underlying truth. However, the second survey comes with a change in distribution ...
5
votes
4answers
219 views

Bias induced from model selection

I am trying to understand the following sentence Cross-validation and information criteria make a correction for using the data twice (in constructing the posterior and in model assessment) and ...
2
votes
0answers
64 views

Adjusting for selection bias in a structural topic model

I want to build a structural topic model that adjusts for selection bias into the sample of entities about whom documents are written. I wanted to use the stm R ...
1
vote
2answers
1k views

Different forms of Inverse Mills Ratio & their interpretation

I have noticed different authors using different forms of IMR, i.e., $\frac{f(x)}{F(-x)}$ or $\frac{f}{(1-F(x))}$ depending on whether they are modeling selection or non-selection in the first-stage ...
10
votes
1answer
16k views

Interpretation of coefficient of inverse Mills ratio

How do you interpret the coefficient of inverse Mills ratio (lambda) in two step Heckman model?