regression

  1. N

    Significant treatment*pretest interaction, but interaction not shown with regression lines

    Hello, I have found that the interaction treatment by pretest is significant. However, the interaction is not depicted on the scatterplot (see attachments). Am I doing something wrong or can I say that the interaction is outside the range of possible test scores (0-10) and that the assumption...
  2. N

    Can this problem be modeled?

    I have a question about whether I can model in a way that solves this problem: Suppose a swimming coach has 100 athletes and only cares about the distance they can each swim in 5 minutes. From this, he sets a baseline expectation of each swimmer’s "5-minute distance" expectation that is...
  3. M

    Recreating logistic regression model in SPSS

    Hello everyone :) I would like to ask for advice regarding recreating a logistic regression model (please see the picture attached). I am working with household level data (English Housing Survey) and on the top of the already present household-level variables, I would like to construct...
  4. S

    Help with interpreting log in regression

    Good morning, I am new to this forum and would like some help with the interpretation of the following regression. I hope I am in the right place. lnWaste = +A(lnGDP) +B(lnGDP)2 I have found coefficients for lnGDP= -1.85 and for (lnGDP)2=0.1 Now I am trying to give an interpretation of what...
  5. Reductionist

    pre-publication testing of one-click auto-analysis tool

    Hi all, I’m a psychometrician at Penn (https://scholar.google.com/citations?user=TlO7ZTsAAAAJ&hl=en) and wanted to get your feedback (as students, faculty, or private sector folks) on a new tool I’m developing for one-click automatic data analysis: https://mooremetrics.com/deedive All you have...
  6. T

    Logistic regression in Stata with binomial dependent variable 3-level categorical predictor variable

    Hi, I'm doing a logistic regression analysis with a binomial outcome variable (Yes / No). My main predictor variable is categorical and has 3 levels. I'm also including categorical and continuous confounding variables as predictors. What is the best way to convert my outcome variable from...
  7. A

    How to interpret the intercept in a regression model which has a categorical covariate?

    I have a regression model with some response Y and covariates height, weight, age, sex. Sex is the only categorical covariate and it takes on the value Sex = 0, for female Sex = 1, for male I want to interpret the intercept of this model, that is the estimated mean value of Y when all the...
  8. A

    How to choose between two regression models when one has a higher adjusted R^2 and the other has a lower BIC?

    I have two regression models with different number of covariates/predictors. After performing a subset selection, the remaining two choices are Model 1, which has 7 covariates and a lower BIC. Model 2, which has 11 covariates and a higher adjusted R^2. Using the BIC criteria, you select the...
  9. M

    Replacing regressor instead of 2SLS

    Hi, can someone explain me why it is usual to run a 2SLS if we are not "satisfied" with one variable and using an instrumental variable to adjust the model? (I am just talking about the just-identified case) Wouldn't it be easier just to replace the variable with the new one, so we have a new...
  10. R

    Interpretation of interaction terms in a multiple linear regression

    I try to improve my statistical knowledge and right now I am working on a regression that contains interaction terms. I am currently investigating the effects of different variables (a1, a2 etc.) on the quantity of chairs sold in a transaction (dependent variable). To see if effects are...
  11. R

    Help to formally write down a linear regression

    Hello altogether, i am currently analysing a dataset of 10,000 transactions. I am analysing the effect of different advertising campaings on the quantity of chairs by using multiple linear regression model with zip code and day dummies. I am interested in formally writing the regression model...
  12. J

    IVs and moderator variables correlate in three-way interaction - problematic?

    Hi everybody, let's assume I hypothesize: H1: A direct effect of X1 on Y H2: A direct effect of X2 on Y H3: A two-way interaction between X1 and X2 H4: A three-way interaction between X1, X2 and X3 H5: A three-way interaction between X1, X2 and X4 and run the following OLS regressions to test...
  13. S

    Constant not sig. in multiple regression - does it matter?

    I did a hierarchical multiple linear regression in SPSS with three predictor variables. All the variables have high F-values and are highly significant at each step of the model, but the constant is not significant (0.079) in the last step. Should I disregard all the results just because of...
  14. S

    Regression Question for Measuring a Corporate Campaign

    Hi everyone, I hope you are all having a great day. Currently, I am trying to measure the effect of an in-store campaign that deals with sampling items. I have 80 stores (40 control and 40 test). I have many interesting variables, such as average local income, number of competitors within X...
  15. D

    What model should I use?

    I have a longitudinal survey (5 waves) that collects a health index (from 0 to 100) and some risk factors and socioeconomic characteristics. I want to develop a model that will predict this health index (with consistent biographies, meaning that the predicted health index should not be...
  16. G

    Random Regression in R

    I am a student. I have some knowledge of mixed regression models. I would like to implement Random Regression in R. I found "Random Regression Models" by Schaeffer (http://animalbiosciences.uoguelph.ca/~lrs/BOOKS/rrmbook.pdf) helpful. I have also read "MCMCglmm Course Notes" by Jarrod Hadfield...
  17. I

    Regression analysis across multiple data sets

    Hi All. I'm new to this forum but I have a background in stats and in business/social science research. I'm in the early stages of designing a research study that will analyze a large dataset for about 100 publicly traded companies. There will be about 10-20 independent variables for each...
  18. L

    Inverted U-shape estimation

    Hi, I am currently writing my master dissertation about the impact of corporate income tax reduction on the competitiveness of nations. It might be probable to assume that a reduction of corporate income tax will have a certain effect depending on the level of corporate income tax already...
  19. P

    Statistical Test for multiple choice questions

    I Iaunched a survey recently where I have the following types of questions - 1) A multiple choice question (where users can mark more than one correct answer), let's call it variable a. 2) A single choice answer type question (radio button type), let's call it categorical variable b. 3) A...
  20. G

    distance from expected in terms of standard deviations

    assume I am predicting home runs, assume all player bat the same number of times, so we can do this by total home runs, and not home run rate) from a player based on past experience. I have a linear regression model for one period of time that determines the model, and I then run 100 players...