All Questions
Tagged with categorical-encoding interpretation
34 questions
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44
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Is the intercept of a complex sum-coded regression basically useless for interpretation? Maybe even for some simple models?
In regression analysis, one may choose to code categorical variables differently depending on interpretability considerations. One such coding scheme known as sum coding (a kind of effect coding ...
- 262
4
votes
2
answers
280
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Interpretation of dummy-coded variable
I have a dummy variable, with 1 meaning the years in which an historical event took place and 0 meaning the years in which it didn't take place. I used 0 as the reference category. When the regression ...
- 75
4
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2
answers
398
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Interpreting when a regression coefficient is significant
Consider the following regression model:
$y_i=\beta_1+\beta_2x_{i,2}+\beta_3x_{i,3}+\beta_4x_{i,2}x_{i,3}+\epsilon_i,$
where $\epsilon_i\sim N(0,\sigma^2).$ Here, $x_2$ is binary variable
$$X_2 =
\...
- 309
1
vote
1
answer
92
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Interpretation coefficients categorical variables
I am working with a large panel dataset studying many companies over a long period of time. Some of these companies receive a negative outlook from an analyst during the sample period. Similarly, some ...
- 363
1
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1
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2k
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Interpreting Correlations with Dummy Variables
I am working through a paper about grad student "satisfaction" (as measured by a survey), and descriptive statistics are given in a table that looks like this:
The "experience of ...
- 113
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1
answer
120
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Interpreting regression coefficients with partial dummy vs. effects coding and multiple factors
I have been working with a data file in R that contains two primary categorical variables : study location (study, 19 levels) which is a nuisance variable and race (4 levels) which is the outcome of ...
- 63
3
votes
2
answers
131
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How to interpret dummy variables and interactions terms on dummy variables in a regression?
Suppose I have a linear regression form of
$$
\log(Y) = \beta_0 + \beta_1X_2 + \beta_2X_3 + \beta_3X_1Z + \beta_4X_2Z + \epsilon
$$
where $X_1, X_2, X_3$ are binary and $X_1$ is omitted as a reference ...
- 4,260
2
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1
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57
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How do I interpret a regression model when there are impossible additive effects?
Let's say I have a model of count data as a function of the month of the year along with an additive effect of season (factor with 2 levels Wet and Dry which correspond to Jan - June and July to Dec ...
- 1,031
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20
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Help determining model and interpreting coefficients of log-linear relationship
I am trying to determine if the hospital I work at should open a new unit for admissions. I intend to do this by correlating patient assigned unit and length of stay in days.
So far, I have determined ...
- 1
0
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1
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162
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Interpreting categorical variables with reference level in linear model
I wonder how should I report the results of categorical variables with reference level in linear model?
The response variable of my model is Duration (time taken to reach 25C for an animal model). My ...
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5
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1
answer
912
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Interpreting standard error for dummy variables in linear regression models
Is there any way to interpret the standard error of dummy variables created to represent a categorical variable in a linear regresion model? I saw a great mathematical explanation here, but I am still ...
1
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1
answer
46
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How to report coefficients for main effects?
Suppose I run an OLS regression as follows:
Y = γ1 + γ2*X + γ3*(D*X)
where D is a dummy variable. I excluded one dummy variable, so the effect is in γ2 and γ3 must ...
- 345
0
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0
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313
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How to interpret independent dummy variables in logistic regression?
I have both quantitative and dummy independent variables in my logistic regression. Dependent variable is binary. I have 2 questions.
How to interpret a quantitative variable that is negative?
How to ...
- 83
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0
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793
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Missing outputs or coefficients from multiple linear regression?
I have a multiple linear regression I have completed below:
...
- 155
1
vote
1
answer
619
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Interpretation of two dummies interacted with one continuous variable
I am currently looking at the following equation using Stata and unsure of how to interpret the interaction terms when there are three variables interacted together (2 binary variables and one ...
- 11
1
vote
1
answer
373
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Elasticity of a 0-1-2 dummy variable in a log-log model
We know from the following sources,
"Halvorsen, R. and Palmquist, P., The Interpretation of Dummy
Variables in Semilogarithmic Equations, American Economic Review,
Vol. 70, 1980, pp. 474-475.&...
- 175
1
vote
1
answer
127
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Interacting main regressor of interest with a region indicator variable, do I interact all controls with the indicator as well?
Lets say I am running a regression at the state year level as the following:
$y_{s,t} = \beta_o + \beta_1 x_{s,t} + controls_{s,t} + \mu_s + \tau_t + \eta_{s,t}$
Where x is the regressor of interest, ...
- 711
1
vote
1
answer
81
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What is the correct way to test multiple dummies?
I'm discussing a topic with classmates and the textbook does not address our concerns. In the following model:
$$wage = \beta_0 + \beta_1 female + \beta_2 educ + \beta_3 (female \times educ) + u$$
it ...
- 127
0
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1
answer
2k
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How do I interpret the coefficients of the reference group for a linear regression with two dummy variables as regressors in R?
I'm using R to fit the following linear regression models with the popular "mtcars" dataset:
...
- 129
1
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1
answer
1k
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Variables significant when changing reference category?
I'm doing a research about risk tolerance and demographic factors using a logistic regression.
When I first included generation (Z Y X BB) in my model with the baseline of BB, Z Y X yield ...
- 21
2
votes
2
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386
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Interpreting the coefficients of indicator variables in regression equation without indicator term
Suppose we were trying to estimate the impact of $Size$ of a house on its price while controlling for whether or not the house is located by the water. Suppose we constructed a dummy variable for ...
- 239
0
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2
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36
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Methods or processes for discovering the major reasons for linear regression coefficients?
Other than inspecting data at random, what are some statistical or graphical processes or methods for determining the major reasons for coefficients in linear regressions?
Example
Suppose we have ...
- 303
0
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1
answer
98
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Interpretation of linear regreassion output when one categorical variable is represented as several dummies
I have a question regarding the interpretation of a linear regression output. In my data I have one independent categorical variable (condition) with five values which I represented as four dummy ...
- 35
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1
answer
46
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How do I introduce control variables in a regression where the I am comparing coefficients to the base?
I am running regressions where I need to compare the coefficients with the base, but I am a little confused about how to introduce the control variables.
My regression looks as per:
...
1
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0
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213
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Testing for parallel trends in panel data/diff-in-diff with only 4 time periods
I am trying to test for common trends on Stata using coefplot, with 4 dummies for each time period (where they equal 1 at time t and if the individual is in the treatment group).
However, clearly ...
- 11
1
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0
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99
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Interaction term btw. binary and continuous variable - dropping the intercept? [closed]
I run a linear regression with many dummy variables (in total 10). Thus to avoid the dummy variable trap, I dropped the intercept and included all dummy variables.
Now I'd like to have a look at the <...
- 11
4
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1
answer
382
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Can I remove a dummy variable when it is not significant by itself, but its interaction with another variable is?
I have the following model based on the financial returns of a company as a dependent variable of a stock market index, and a dummy variable interacting with USD exchange rates to my currency. The ...
- 173
1
vote
1
answer
58
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Multiple regression with a odd-numbered Likert items
In the questionnaire, individuals were asked to pick from an odd number of options (5 or 7) how much they agree with the statement (from completely agree to completely disagree).
Now, if there where ...
- 111
2
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1
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562
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How to interpret interaction dummies of multiple categories and main effect
I have a panel data crosscountry regression with following structure ($y$ as a drug addiction rate of the country, $x$ as number of homeless of the country and $m$ as HIV infection rate of the country)...
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2
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2
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2k
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Dummy variables interpretation in multiple regression
If I have the following maximum model in an analysis:
$y = b_0 + b_1 x_1 + b_2 x_2 + b_3 x_3 + b_4 x_4 + b_5 x_5 + b_6 x_6$
where
$y$ = home price
$x_1$ = number of rooms
$x_2$ = number of ...
- 81
0
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1
answer
74
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How many dummies should I create
I have sales data for different locations. My outcome variable is making a sale (1,0) and my IVs are about 200 different locations, handling time etc.. I ran a logistic regression using the class ...
- 101
3
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1
answer
2k
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What to do in a multinomial logistic regression when all levels of DV are of interest?
I am running a multinomial logistic regression. The outcome variable is categorical with seven levels. The predictor is binary.
Very briefly, the experiment is such that I am asking whether a ...
- 2,701
1
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0
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216
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How to interprete logistic regresion using Eviews having dummy variables
I need your help with logistic regression analysis. My dependent variable is a dummy variable: 0 fails 1 successful.
Method: ML - Binary Logit (Newton-Raphson / Marquardt steps)
variables and ...
- 11
1
vote
1
answer
8k
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Interpretation of dummies (several variables and categories!)
I am trying to figure out how to interpret the coefficients when using several qualitative independent variables of which some have more than two categories. I found this short article that touches ...
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