Contents
What does C mean in Stata?
Stata handles factor (categorical) variables elegantly. If you want to interact a continuous variable with a factor variable, just prefix the continuous variable with c.. You can specify up to eight-way interactions.
What does Varlist required mean in Stata?
11.1.1 varlist If no varlist appears, these commands assume a varlist of all, the Stata shorthand for indicating all the variables in the dataset. In commands that alter or destroy data, Stata requires that the varlist be specified explicitly. See [U] 11.4 varname and varlists for a complete description.
What is the test command in Stata?
The test command, when applied to a single hypothesis, produces an F- statistic with one numerator d.f. The t-statistic of which you speak is the square root of that F-statistic. Its p-value is identical to that of the F-statistic.
What does == mean in Stata?
The double equals, ==, is used to test for equality. It is sometimes called logical equals because it is part of a logical test that returns either a one (true) or a zero (false).
What is p value in Stata?
The p-value is a matter of convenience for us. STATA automatically takes into account the number of degrees of freedom and tells us at what level our coefficient is significant. If it is significant at the 95% level, then we have P < 0.05. If it is significant at the 0.01 level, then P < 0.01.
How to define a male effect in Stata?
First, when you specify an interaction in Stata, it’s preferable to also specify whether the predictor is continuous or categorical (by default Stata assumes interaction variables are categorical). The interaction is the male effect for a particular exercise type.
What is the variable yr _ RND in Stata?
The variable yr_rnd is a categorical variable that is coded 0 if the school is not year round, and 1 if year round, see below. The variable meals is the percentage of students who are receiving state sponsored free meals and can be used as an indicator of poverty.
How to regress interactions in Stata Chapter 6?
6.2.1 Analyzing simple effects using xi3 and regress In order to look at the simple effects of collcat at the different levels of mealcat, we will use the @ symbol instead of * to indicate that we want the interaction terms to reflect the simple effects of collcat at each level of mealcat.
How to create an indicator variable in Stata?
We can use the xi command to do the work for us to create the indicator variables and run the regression all in one command, as shown below. When we use xi and include the term i.mealcat in the model, Stata creates the variables _Imealcat_2 and _Imealcat_3 that are dummy variables just like mealcat2 and mealcat3 that we created before.