Questions tagged [heterogeneity]
Use this tag for questions in the context of meta-analysis; use [heteroscedasticity] in the context of regression modeling. Heterogeneity arises when the primary studies are not drawn from a single population.
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Characterizing and comparing the heterogeneity of ordinal responses from survey
Let us consider the following setting:
We have two groups Q1 and Q2 of questions
Several participants answer all questions using a single ordinal scale A, B, C or D for all questions.
Then, I want ...
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How to tell if a covariate modifies the effect if each subgroup has different number of participants?
Im working on a meta-analysis of interventional studies that compare between two kinds of interventions.
After pooling the studies together, the heterogeneity using I squared was 0%.
Afterwards, I ...
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Removing studies from subgroup analysis
Im currently working on a meta-analysis of randomized controlled trials, which examine the use of a certain graft in certain surgical intervention. In my pre-specified protocol, I planned to perform a ...
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Control function interact treatment with residual
I am going through an old metrics tutorial using instrumental variables regression. In one question we are supposed to estimate the Average Treatment Effect (ATE) using a control function approach. We ...
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Spatial heterogeneity test for Negative Binomial Regression: Which test should you choose?
I will do a spatial heterogeneity test on my negative binomial regression model. Initially I will use the Breusch-Pagan Test with the R syntax:
...
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What does scale heterogeneity mean in the generalized multinomial logit models?
I have learned that one property of multinomial logit models or the data used to build these models is scale heterogeneity. What does Scale Heterogeneity mean in the sphere of multinomial logit models?...
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How to compute the total standard deviation of the (true) effect sizes, σ, in random/mixed-effects meta-analytic models?
I have the following meta-analytic model (effect sizes nested within samples):
...
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Econml summary() interpretation [closed]
I just started using EconML library, I would like to ask what does the output of inference summary mean? what exactly is the prediction/inference doing here?
UPDATE: Also, I don't understand about the ...
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Outlier study in a meta-analysis
Im currently working on a meta-analysis of randomized controlled trials (RCTs).
These RCTs have reported their outcomes at different time points.
The maximum follow-up points were as follows: 1 months,...
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Calculating heterogeneity of groups within a sample
I am currently trying to find the proper statistics measure to calculate the heterogeneity of a group of students. The problem is the following:
I have a population of students, divided into groups of ...
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Difference-in-difference robust to heterogeneous treatment effect - extension of an article
I am trying to extend the results of Gendron-Carrier et al. (2022) article published in the American Economic Journal : Applied Economics which is about the effect of subway opening on pollution.
I ...
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Subgroup of one study in a meta-analysis
Im currently working on a meta-analysis of randomized controlled trials (RCTs).
These RCTs have reported their outcomes at different time points.
I decided to split the data of these studies into sub-...
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Statistical tests on non-homogeneous area
Observing a highly non-homogeneous area, I would like to statistically observe and evaluate certain phenomena. Below is an example set of fields, segmented into 3 zones (Z1, Z2, Z3) using a clustering ...
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How to calculate the proportion of heterogeneity accounted for by moderators in a multi-level random-effects meta-analysis?
I have conducted a multi-level random-effects meta-analysis using the "metafor" package in R and have been asked by a reviewer to report the proportion of heterogeneity accounted for by ...
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Seeking help identifying the right causal model for my research
I am conducting a quasi-experimental research where the treatment is of varying intensity. For e.g., to investigate the impact of CEO's transgression on the stock market behavior (hypothetical; not my ...
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Group level covariates for mark recapture
I'm working on investigating capture heterogeneity in acoustic signals by comparing mark-recapture models between two types of congruent data, photographic and acoustic. We have information on the ...
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Is it reasonable to report $I^2=0$ with confidence interval [0, 100] in a meta analysis?
Is it reasonable to report $I^2$=0 with 95% confidence interval [0, 100] in a meta analysis manuscript?
I was not sure since the CI covers all possible values.
$I^2$ is a commonly used heterogeneity ...
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One or multiple regression/s?
Say your equation in a paper has 6 coefficients, one being your main interest (dummy for Disability == Having at least one disability: coded 0/1).
This estimation is done. BUT you want to dig deeper, ...
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Sample selection bias as internal bias under heterogeneous effects
I have been reading a lot about the extent to which sample selection biases that come from truncated samples (e.g., Heckman selection situations) are not only externally biased, which is more commonly ...
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metafor's rma gives conflicting (zero) values for tauˆ2 and Iˆ2 compared to Review Manager?
I'm having a problem with metafor's rma-function, which inappropriately (I suppose!) gives both tauˆ2 and Iˆ2 zero values. This questions was previously asked on Stack Overflow, and then it was ...
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Should I expect lower R2 with meta-regression in meta-analyses with low heterogeneity?
The question in short: Should I expect lower R2 values in meta-regression performed in a meta-analysis with low levels of heterogeneity?
In meta-analysis, I2 represents a ratio of between-study ...
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Can HAR models also be applied on non-volatility data?
Currently, I am trying to forecast several cash flows of accounts receivable and payable of a company. I want to apply the HAR model due to the simple structure of the model; it incorporates the short-...
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3
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Causal inference where potential outcome is somehow "violated"?
The fundamental problem of causal inference says that only one potential outcome is observed for each unit.
What happens if both outcomes from control and treatment can be observed? Can we still make ...
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Conditional Average Treatment Effects
Suppose I am interested in understanding the effectiveness of two type of medicine, A and B.
In the usual setting, each patient is considered an experiment unit, and is assigned one of the medicine. ...
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causal tree in a diff-in-diff setting
I am new here. Does anybody know how to set up a causal tree in a diff-in-diff setting with observational data? Is anyone aware of any papers where this has been done?
Any help would be much ...
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What Heterogeneity/Between-Study Variance Estimator to use in a Reliability Meta-Analysis/Reliability Generalization Random Effects Model?
This is an extension of this question but for reliability generalization studies.
Could anyone recommend a between-study variance / heterogeneity () estimator and method for computing confidence ...
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How do I write the Jeffreys prior for error variances in stan? $p(\mu, \sigma_1^2, \dots, \sigma_C^2) \propto \Pi{ \sigma_i^{-2}}$ [closed]
I need to model the Jeffreys prior for error variances in a heteroscedastic ANOVA design in rstan.
That is to say, $\pi(\mu,\sigma_1^2,\dotsb,\sigma_C^2)\varpropto\Pi_{i=1}^{C}\sigma_i^{-2}$.
Is the ...
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What repeated measures statistical tests should I use with uneven sample size and parametrical/nonparametrical distribution?
I'm looking for a way to measure significance + variance homogeneity/heterogenity
First of all I tested my data for normality and it's not always parametrical, so I think that I should use different ...
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What does "sharp design" mean in Chaisemartin (2020)'s paper compared to Goodman-Bacon (2017)'s paper?
When studying the paper of Chaisemartin (2020) comparing to Goodman-Bacon, 2017's paper regarding heterogeneous treatment effects, a commentator said that Chaisermartin's papers have more of a sharp ...
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How does tau squared (between-study variance) differ for network meta-analysis versus pairwise meta-analysis?
I'm currently trying to replicate a random effects network meta-analysis in Excel.
When estimating between-study heterogeneity, I can calculate Cochran's Q just fine via:
$$Q=\sum w_i(y_i-\hat\theta)^...
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What is extropy?
While searching for the answer to a statistics problem, I came across the term extropy, which was - and to a large extent still is - unfamiliar to me. A quick google search revealed that it is the &...
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Multi-level meta-anlaysis
I'm conducting a meta-analysis in which some of studies reported multiple effect size as they examined the outcome on multiple groups of glucose-lowering drugs. So, a three-level meta-analysis was ...
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Which type of cluster analysis to perform?
I am trying to explain variability in the outcome, and understand factors that may be associated with different clusters? I am confused as to which clustering method to use to obtain 3 clusters as ...
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EM algorithm for normal mixtures with constraints
I have $G$ groups, each with $N_g$ data points $y_{ig}$, $g=1,\dots,G$ and $i = 1, \dots, N_g$. The group for each data point in observable.
I want to estimate the normal mixtures model with $K$ ...
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How to choose between different estimators for tau in meta-analysis?
The question is relatively simple although it may won't be possible to answer at all.
In meta-analysis using random-effect model, we can choose between several different methods for estimating tau (e....
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What are the QE and QM testing in a meta-analysis, and how do they relate to each other?
I am working on a meta-regression model with a moderator variable (a factor), and so am using the QE and QM tests to explore the importance of the the moderator. I understand the QE tests for residual ...
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Fixed effect OLS with normalized coefficients in R
I want to estimate the following fixed effects regression:
$$
Y_i = \gamma_{m}+ \lambda_b + \delta_{gb}D_{igb}+\varepsilon_i,
$$
where $\gamma_m$ is municipality fixed effect, $\lambda_b$ is birth ...
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Clustering on n features while maximizing the heterogeneity on m remaining features
We have a random vector $X\sim p(X)$, and a set of realizations of the random vector $S=\{X_i\}_{i=1}^N$. The random vector has $n$ continuous and $m$ categorical features. I want to cluster $S$ so ...
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Continuous (not categorical) measures of diversity?
Which measures of diversity are used where? When I search for diversity indicators I find the Simpson and Shannon index, but these are both for categorical data. If I have data with some structure (e....
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Correct interpretation of Tau and Tau^2 in meta-analysis of different measures
Simple question. Given that Tau is defined as the estimated standard deviation of underlying true effects across studies (and, accordingly, Tau^2 as the variance), how can I interpret this data in ...
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Identifying the correlation between a slope and a level
Throughout this post, I assume at least second moments exist. Consider a heterogeneous linear treatment effect model of the form:
$$Y_i = \alpha_i + \beta_i X_i$$
where $\alpha_i, \beta_i$ are ...
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How can I control for unobserved heterogeneity with cross-sectional data?
I want to run a cross sectional regression for 700 firms in the US to test the impact of working capital on profitability. I specifically want to limit my analysis to the 2008 financial crisis and ...
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658
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Multi-Factor Kruskal Wallis Test in R
I have a dataset where the response variable is a non-normally distributed proportion and is heterogenous with respect to all factors. I cannot seem to transform the response variable into anything ...
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Meta Analysis - Find the pooled Odds Ratio, given each subjects OR, Lower and Upper Limit and Z-test values
I have a problem I have been working on but can't seem to understand how to go about solving, and any help would be most appreciated.
My Problem:
I have been asked to find the pooled OR and it's 95% ...
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Can I test whether there is a group of observations in a dataset having a treatment effect in the opposite direction with respect to the ATE?
Suppose that I'm looking for the effect of a shock (for example, a natural disaster, or the current Covid pandemic) on given outcomes, where each observation corresponds to a different person. I ...
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DiD with time invariant and time variant treatment?
I am currently working on a project that seeks to study the impact of the subprime crisis on family firms and non-family firms. In this, I have imagined to use a DiD estimator to account for ...
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Heterogeneous Treatment Effects with Continuous Treatment (e.g. using BART)
Overview:
Most of the causal inference literature (both theoretical and applied), I have seen on heterogeneous treatment effects, only considers the case with a binary treatment $T\in\{0,1\}$. However,...
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Group Heterogeneity in a Meta-Analysis - Layman's Terms
EDIT: I now believe this question was based on misguided information. See my answer.
I'm looking through this meta-analysis (of studies on the effects of mindfulness on healthy individuals) for some ...
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Transforming Heterogeneous Treatment Effect Models (in EconML) into Average Treatment Effect Model (from DoWhy)
This question relates to the steps one would need to take in order to reproduce an answer from the DoWhy tutorial, using the EconML library code for heterogeneous causal effects.
In DoWhy, there is ...
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Causal inference for multiple treatments with an observed set of properties
Note: I have rewritten this question quite a lot, because pzivich's answer made me realize that I had not formulated it accurately enough . In order to give the original context of pzivich's answer, I ...
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