11 views

### Can [single] Linear Regression be inferred from Multiple Regression? [duplicate]

A student posed a question: she has observations from two, independent groups for variables Y and X. She drops them on a ...
9k views

### How to test whether a regression coefficient is moderated by a grouping variable?

I have a regression done on two groups of the sample based on a moderating variable (say gender). I'm doing a simple test for the moderating effect by checking whether the significance of the ...
• 233
2k views

### Difference between temporal trends

I have a dataset with observations form a population that have been described graphically as an annual trend. For example – male infection rate per year, female infection rate per year. The ...
• 371
2k views

### ordinal regression or Spearman correlation?

I am conducting research investigating two different groups of women: one group of Short-Stature Women (SSW) and another with Non-Short Women (NSW). We have the hypothesis that SSW has an inaccurate ...
1k views

### What is the difference between a linear regression with a dummy variable and two separate regressions for each group?

I am interested in the connection between a multiple linear regression including a dummy variable (0/1) and two separated regressions split up by this dummy variable, i.e. two distinct regressions for ...
• 316
342 views

### Moderated regression and separate models give slightly different results

When I run a regression with an interaction term (composed of one continuous variable and one binary variable) and several covariates, I get an interaction term value of -6.52. However, when I run two ...
• 365
1k views

### How to perform linear regression on clusters of data

Suppose I have 2 clusters of data: $\{(Y_{1i}, X_{1i})\}_{i=1}^{n_1}$ and $\{(Y_{2i}, X_{2i})\}_{i=1}^{n_2}$, and I'm interested in running a simple linear regression on each cluster. I assume that ...
• 2,673
989 views

### Alternative to Chow test for equality of estimates, when the data for the 1st group is not available

My goal is to compare published regression weights estimated from a sample in another country, with those of the same model established on our data.There is ample evidence on the web that a Chow test ...
1 vote
716 views

### Standard error of reconstructed slopes (coxph/coxme)

I have performed mixed effect Cox hazard regressions, and reconstructed the slopes to get group specific slopes (e.g. sex-specific responses to the explanatory variable). I aim to test whether the ...
• 892
696 views

### significant difference between coefficients

What is the correct way to test for significant differences in parameter estimates in the following case: I have a dependent variable (height for age) and a independent variable (household state ...
252 views

### How to prove that a separate linear model for each class is equivalent to using interaction with the class?

I learned in this question's comment by @amoeba that Also, the difference between "building separate models" and "using categorical variable" is not clear to me. ...
• 37.2k
295 views

### How to test if the difference in the value of the coefficient of X is different between subgroups in R?

I have a simple linear model (earnings ~ age), and I want to test if the coefficient on age is significantly different for separate subgroups in my data (those with a bachelor's degree, and those ...
1 vote
173 views

### Performing t-test for coefficients using bootstrap

I am having some difficulties reconciling a test for the difference in means using a standard test and the bootstrap. It would be great if someone could tell me what is going wrong in the code. I run ...
• 33
155 views

### Pros and cons of different methods for comparing betas in regression

In my line of work, we often hypothesize that one continuous predictor will have a stronger relationship with some outcome than another closely related (i.e., collinear) continuous predictor. We fit a ...
• 193