A situation where the effect of an explanatory variable may depend on the value of another explanatory variable.

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2
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1answer
14 views

confidence intervals around lines from glmer in lme4

I have spent a large amount of time trying to figure out how to generate a desired plot, and was wondering if any one can help. The plot is to illustrate an interaction between 'time' and 'group' on a ...
0
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0answers
15 views

Multilevel models benefits vs. separate group models

What are the benefits of multilevel models vs. running a separate model for each group? My understanding is that MLM offer a method to effectively model interactions against all the base predictors. ...
0
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0answers
13 views

Interacting lagged variable with dummy: factor variable and time series not allowed [migrated]

I am trying to run an Arellano-Bond regression to explore whether the impact on my dependent variable varies according to exchange rate regime, i.e. does economic growth differ when remittances go up ...
1
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0answers
23 views

In stratified analysis should beta estimates from main effects remain constant when an interaction is added? [on hold]

I run stratified analyses by a factor variable and found estimates for both groups to be significant. Then I have included an interaction term. The results from this analysis revealed that the ...
0
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0answers
27 views

interpreting a 3 way interaction between categorical variables with mixed model with random effect

I have ran a glmer analysis with R. This question have been comment regarding three way interaction for ANOVA models. this is clearly not the same thing as a general linear mixed model first because ...
0
votes
1answer
11 views

Nesting v. interaction in LMM

I have a continuous response variable, a continuous predictor (P1) and a variable (elevation, P2) that could be treated either as continuous or categorical (I guess?). I also have an ID as the random ...
0
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0answers
16 views

How does one interpret a demeaned log interaction term?

I am having problems interpreting my regression equation. I want to know the effect of an increase in variable $x$ on $y$ for different values of $z$, but as it's in logs and the interaction term is ...
0
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0answers
20 views

Linear Logistic Regression where Dummy variable is strictly dependent of other covariates

I want to do a logistic regression for something being granted or not. In this I have independent variable that is dependent of a dummy variable. For example, I want to regress ...
1
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2answers
45 views

Large differences between raw (plotted) data and least-squares means from mixed model

I’m analysing data with mixed-models (using the afex package which I believe is based on lme4) from an experiment that had a ...
0
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0answers
11 views

Two-way interaction of shared variable in econmetric

I am trying to build a fixed effect model and this is my model at the moment X + Y + Z + XY + XZ My hypotheses are interested in XY + XZ but i have consulted a few people who told me in order to ...
0
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1answer
25 views

How to show the combined effect of two covariates in a simple regression?

Say I want to build a simple model, and I have four variables available to me: Age, gender ($D_1$, 1 is female, 0 male), income, and whether the person is Hispanic or not ($D_2$, 1 is Hispanic, 0 ...
2
votes
1answer
26 views

Dummy variables for people and time

I have panel data for people over a number of years. People can be categorised based on a certain characteristic, X. Individual's yearly observations can be categorised based on whether a particular ...
0
votes
1answer
10 views

Interpretation of Interaction Term with Dummy [duplicate]

I am trying to interpret the following model: y=a1+a2*x+a3*d+a4(x*d)+e where y= growth rate x=debt d= dummy high debt ...
0
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0answers
13 views

Interaction model with measurement error without replicate measurements

I am currently working on a simple OLS model with two independent variables and one dependent variable: \begin{equation} \ Y_i = \beta_0 + \beta_1 X_i + \beta_2 S_i + \beta_3 X_iZ_i \end{equation} ...
1
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1answer
48 views

Boosted trees and Variable Interactions

How can one see in a Boosted trees classification model, which variables interact with each other and how much? I would like to make use o this in R gbm package if possible
0
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0answers
26 views

Multicollinearity error in interaction model

I have a question about multicollinearity in the ordinal logistic regression. I have a cohort binary variable (i.e. 1 = canada, 0 = U.S. ). I then have a variable with 3 levels called it Smoking(1 = ...
0
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0answers
24 views

Interaction in Multiple Regression with Lagged Variable

The problem I'm trying to solve is as follows: X is a strong predictor of Y, both measured at time T, controlling for other IVs. Based on theory, some people say this supports the hypothesis that X ...
2
votes
0answers
35 views

How can I get slope and standard error at several levels of a continuous by continuous interaction in R?

I'm comparing the slopes of several different response variables (DVs; representing different populations) to a set of predictors (IVs). For some DVs a 2-way interaction (continuous by continuous) is ...
0
votes
1answer
35 views

Interaction term and partial least square regression

I am investigating the association of air pollution with birth weight. Given that there is collinearity between air pollutants, I chose to use PLS regression. To my understanding, we could use ...
1
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0answers
41 views

How to determine if an interaction has opposite effect?

I have performed an analysis in which I have two continuous variables interacting as follows: lm(response ~ var_a * var b) var_a = float values between [0-2] ...
0
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0answers
16 views

VIF & CI in Regression with Dummies and Interaction Terms

I am checking my dataset for multicollinearity using VIF and condition indices(CI).My dataset is cross-sectional macroeconomics data (n=75). I have six independent variables (x1,x2,x3,x4,x5,x6) plus ...
1
vote
1answer
25 views

Interaction term becomes more significant

Model(1): Y = A + B + $W_1$ + A*B Model(2): Y = A + B + $W_{1,2,3,4,5}$ + A*B A ranges from 0 to 70 while B ranges from 0 to 25; W refer to set of controls. In model (1) A (p<0.01) and B ...
0
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0answers
28 views

Interactions Dummies with an Independent Variable

In my model I want to include two dummies ($d_1$,$d_2$) and also the interaction effects of these two dummies with another independent variable, $x_1$. The interaction terms are $x_1\cdot d_1$,$x_1 ...
0
votes
0answers
29 views

Multicollinearity as interaction terms added: Separate or common analysis?

Using OLS, the starting aim of my analysis is to study how different types of credit card contracts affect the dependent variable (y: use of credit cards). I have generated three dummies (v1, v2, v3) ...
0
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0answers
32 views

Quadratic and interacted linear models when one predictor is categorical

In another question of mine, I asked about fitting linear models based on the second-order Taylor expansion: $$ Y = \beta_0 + \sum_i \beta_i (X_i - x_{0i}) + \sum_{i,j} \beta_{i,j} (X_i - x_{0i})(X_j ...
0
votes
1answer
41 views

interactive clustering of a 3D point cloud by changing the granularity

I want to cluster a point cloud in a 3D space (maybe with 200k points). For this I'm locking for a botom up approach. My goal is, that I can change the granularity of the clustering with a ...
2
votes
1answer
45 views

How to decide which main variable is modified by the interaction term?

Given the following linear model $Y=int+aX1+bX2+c(X1*X2)+e$, where $X1$ and $X2$ are the main variables, ($X1*X2$) is the interaction term, and $a$, $b$, and $c$ are the corresponding coefficients. ...
0
votes
0answers
29 views

Best procedure for evaluating group differences in a Lasso regularized regression

I am evaluating 25 predictors (continuous, ordinal, multinomial) on an ordinal outcome variable using a lasso regularized regression. I am using the lasso for variable selection, to determine which ...
0
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0answers
7 views

interaction term in ordinal probit model

I am working on an ordinal probit model. If i plan to introduce an interaction term between a dummy variable and an ordinal variable (having 3 and in some cases 5 categories) , then is such an ...
2
votes
1answer
33 views

Adjusted R-squared: number of terms or independent variables?

When applying a multiple linear regression, does the adjusted R-squared value depend on the number of independent variables in the model or the number of terms? Specifically, I'm concerned that adding ...
1
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2answers
70 views

main effect in logistic regression with the presence of interaction

I just have a question about how to get the main effect in the presence of interaction effect. I have two cohort: say cohort A and cohort B . For cohort A, I have this code as 1. Zero for cohort B. ...
1
vote
1answer
24 views

Continuous vs. categorical variables in interaction terms

My analysis includes, among others, three independent variables: X (interest rate), Y (type of rate; it is a dummy), and Z (likelihood of bankruptcy). I have transformed the latter into a categorical ...
0
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0answers
48 views

Multiple regression with categorical moderator (age) and continuous IV's and DV

I am doing a multiple regression with 6 IV's, 1 DV, and 1 moderator. I am having a problem trying to understand how to get the effect of the moderator which is age group (i.e. 18-25, 26-35, etc.). ...
0
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0answers
44 views

Two-way ANOVA: negative interaction sum of squares?

I am doing a two-way ANOVA. The two variables are both categorical, one with 3 and the other with 2 categories. The count for each category is not equal. The data (only category means) is here: ...
1
vote
1answer
49 views

Multicollinearity and interaction terms

My dataset has 2734 observations (but in some speficitations, that number reduces to 1280). I also have interaction terms (in some specifications, even fourth-order terms). As far as I know, ...
0
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0answers
11 views

effect of modifiers- case crossover

I am studying the effect of air pollution (PM) on health outcomes, and the characteristics that might modify this effect, using the case crossover analysis based on the conditional logistic ...
0
votes
1answer
39 views

How to interpret interaction between a dummy and a continuous variables in ols?

I am trying to examine the association between maternal education and child school test scores using the following equation. $$\small{TestScore_i = \beta_0 + \beta_1 EduYrMom_i + \beta_2 ...
0
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0answers
16 views

Sketching of Graph following Moderated Regression

I'm new to moderated regression and this site and I have a question on deriving the regression equation to sketch the slopes required for interpreting of a moderated regression. All of the other sites ...
1
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0answers
17 views

interaction term not in expected direction

I am conducting a hierarchical regression analysis to test interaction effects. The main variable and the moderator are related to the dependent variable significantly and in expected direction. ...
1
vote
1answer
64 views

Compare linear models with and without an interaction effect

I want to compare the following two linear models: model 1: y = mean + A + B model 2: y = mean + A + A*B Is model 2 equivalent to y = mean + A + B + A*B? Can I ...
1
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0answers
46 views

How to determine the significance of an interaction?

My question is simple: How do you determine the overall significance of an interaction (i.e. the marginal effect of $X$ on $Y$ for different values of $Z$)? But the background is a bit ...
3
votes
1answer
82 views

Can you determine if an interaction exists from a correlation matrix?

Below are the results of a correlational analysis. This table shows the correlations among 8 variables (performance expectancy, ...
3
votes
2answers
62 views

Predicting an output based on whether a variable is above or below a threshold

I want to create a linear regression model to predict an output that uses two different coefficients based on some threshold within the data. For example: df: ...
1
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0answers
35 views

Running 2x2x2 ANCOVA in SPSS

I need to conduct an ANCOVA on my data. While I've taken a number of statistics courses, I have never come across ANCOVAs and I want to get some feedback on the correct way to conduct this analysis. ...
0
votes
1answer
42 views

GAMLSS: model with interaction terms failed

I use gamlss method from library(gamlss) on my full models with interaction terms and try to reduce them with stepGAIC. There are 3 things I want to ask. Do I have to specify a link for the model? ...
0
votes
0answers
12 views

how to analyse an interaction in a within-subjects repeated ANCOVA post-hoc?

I have pre and post measures of attention that I am examining in a within-subjects repeated measures design. I wanted to check the effect of verbal intelligence [VIQ] on my attention[pre/post] ...
0
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0answers
3 views

How to interpret/detect interactions with proportional effects

Assume I have an experiment with 2X2 factors. Let's name the first factor F1 with the levels ...
3
votes
2answers
78 views

How to deal with values that don't exist, as opposed to are missing?

I am working with a dataset where the dependent variable is $y$ (level of use of a line of credit) and the key independent variables are $x_1$ and $x_2$ (two different types of interest rates). Some ...
2
votes
1answer
56 views

How does step function selects best linear Models which includes polynomial effects and interaction effects in R?

I try to find "best" linear models with continuous and categorical covariables with Interaction Effect by BIC. The continuous covariables should have a quadratic effect on the response variable. ...
1
vote
1answer
87 views

Plot regression with interaction in R

I did a regression analysis with the following variables: Predictor = dummy variable, dependent Variable = metric, moderator variable = metric. I now want to show my results in a figure. The ...