regression analysis

  1. A

    Do I need to rescale variables to compare coefficients.

    I'm running a regression analysis. My "Y" variable is Yearly_Spend while my "X" variables are Time_Spent (on website in minutes) and Length (of membership in years). Right now my results show Years has a bigger impact on Yearly_Spend. Do get a true apples to apples comparison of the...
  2. A

    Different coefficients from regression and trendline equation

    I have two variables 'x' and 'y'. I took the natural log of the 'y' variable and then plotted the ln(y) vs x on a scatterplot in excel. I added a logarithmic trendline which seems to fit perfectly. The line equation is y = 1.1282*ln(x) + 12.183 with an R-Squared of 89%. However when I run the...
  3. D

    Logistic regression or something else?

    I have a dependent binary outcome and 6 independent variables. These are measured in the same group of people at two moments in time in a descriptive longitudinal study. I am assessing whether these independent variables increase the likelihood of achieving the binary outcome. I know that I...
  4. S

    regression coefficient as average effect

    In OLS, given the regression equation y = B0 + B1X, why do I often read that B1 represents the average effect of a predictor? I don't get that. For example, data <- data.frame(sex=c("male","female","male","female","male","female","male","female"), DV=c(22,32,34,16,66,34,77,23)) The average...
  5. J

    multivariable regression equation with interaction terms for difference-in-difference method

    I am doing a difference-in-difference analysis on a set of survey data for a health education program and I need to find statistical significance for the difference-in-difference estimate. I know that I find this using a regression. I need to use a regression in a mixed logistic model including...
  6. J

    Why does the “linear regression t-test” return a p-value (two-tailed) from regression that is twice the p-value from ANOVA? (Binary predictor)

    I'm using the "linear regression t-test" guide at https://stattrek.com/regression/slope-test.aspx The guide shows calculating t =b1/SE, where b1 and SE are provided by the regression function (here lm() - using R.) The guide shows the p-value gets doubled as this is a two-sided test...
  7. P

    How to interpret log differences in a partial log-log regression

    I'm currently trying to understand the relationship between firm performance and various independent variables (e.g. firm size, firm profits..). Now, the regression I'm estimating looks like the following: Δlog(firm_performance) = α + β1 Δlog(firm_size) + β2(other_variable) + ε Where Δ...
  8. T

    Regression coefficient interpretation

    Hi, i have run a regression to estimate the impact of couple of variables like growth rate, company size or leverage on the profitability of a firm. I know that if e.g. the regression coefficient for growth is 0,5 a 1% increase in growth rate would yield a 0,5% increase in profitability if...
  9. T

    Why are so many variables in my regression significant?

    Dear everone, For my research I am trying to define the impact of certain elements on a company's goodwill impairment. For my regression analysis I deflated the following variables by the lag total assets: - gdwlia (dependent variable) - ROA - BM - difference in turnover between year t-1...
  10. R

    Multiple Linear Regression: to split or not the data

    Hi all, I'm currently modelling running performance using multiple linear regression. The data has GENDER and AGE as inputs amongst others, the target is RACE_TIME. I've partitioned the data into training and test for cross validation purposes. I've tried a couple of approaches 1) to generate...
  11. C

    SPSS Complex Problem or at least it seems as such

    Here is the issue. I ran a logistic regression a time variable (time to surgery) had a trend of increased infection. Great right. Done? No. This is where SPSS gets tricky and why I might just abort back to SAS like I do sometimes. But lets see. I ran a graph for cumulative infection count...
  12. U

    Linear vs nonlinear regression doubt

    Hello, I am currently working on a study about how much time a chess engine should think per move in a chess game. The inputs (known data) would be how much time is left (in seconds), the evaluation of the engine (centipawns) and the move that is being made. My question is: is it a multiple...
  13. M

    How to split residuals into groups for the Brown-Forsythe test

    I have the following data id 1 2 3 4 5 6 7 8 9 10 11 12 num. responses 16 14 22 10 14 17 10 13 19 12 18 11 cost 77 70 85 50 62 70 55 63 88 57 81 51 I fitted the linear regression model and I got the following residuals: 5.22478992, 4.76260504, -6.38865546...
  14. T

    Interpretation of my results (Significance varies a lot)

    Hi, I have a problem with the interpretation of my results from a multiple linear regression. I want to evaluate the impact of a policy change (X) on an economic indicator (Y) and have included various covariates in the regression (6). The policy change occurred in 2015 and I have data from...
  15. K

    Variable that should appear significant is insignificant

    As part of my University research project, I have decided to study the impact of Immigration on house prices but find that the immigration Variable that should be statistically significant according to literature appears to be insignificant. I don't know whether this was down to the method I...
  16. P

    Regression Analysis for Survey Data on SPSS (For a beginner)

    Hello Everyone, I am very new to SPSS so forgive me if my questions seem overly simple. I am conducting a survey based research project. My dependent variable contains 2 response options: Likely or Not Likely (0 or 1) The independent Variables I am interested in are: Age Category (20-29...
  17. J

    Dummy Variable Help

    Hi, I require checking on how I constructed these dummy variables and see If I did them correctly. Firstly, the data. Time period (1-30) of the study (from 3/18/51 to 7/11/53) Year within the study (0 = 1951, 1 = 1952, 2 = 1953 The first attachment is the set of original data and the second...
  18. P

    OLS Regression Output interpretation (really urgent)

    Hi guys, I have the following output and I really need your help with this: The questions are: a) Regressor X3 is a dummy variable (X3 = 1 if individual belongs to group 1). What interpretation can you give to the corresponding coefficient? b) The dependent variable was generated by the...
  19. S

    How to use a regression equation?

    I have a regression model with 11 predictors developed by a researcher. Among the 11 predictors, in a different dataset, I have 7 of them. How can I modify the previous regression model and account for the 7 predictors only? I know I can develop a new regression model. However, I want to know...
  20. R

    Only Time Fixed Effects for Cross-Sectional Data

    Hi Talkstats-Community. I have been browsing around but couldnt find an answer to my problem. Hopefully you might be able to help me on this. I have a dataset with funds that were launched in the last 40 years and the final performance that they achieved until they were liquidated. This means I...