Contents
What does predict function do in Stata?
predict calculates the requested statistic for all possible observations, whether they were used in fitting the model or not. predict does this for standard options 1 through 3 and generally does this for estimator-specific options 4.
What does XB mean in Stata?
xb calculates the linear prediction from the fitted model. The statistic produced by stdp can be thought of as the standard error of the predicted expected value, or mean index, for the observation’s covariate pattern. This is also commonly referred to as the standard error of the fitted value.
What does _cons mean in Stata?
The last variable (_cons) represents the constant, also referred to in textbooks as the Y intercept, the height of the regression line when it crosses the Y axis. In other words, this is the predicted value of science when all other variables are 0.
How do you create predicted values in Stata?
To create predicted values you just type predict and the name of a new variable Stata will give you the fitted values. For this example, our new variable name will be fv, so we will type predict fv (option xb assumed; fitted values) If we use the list command, we see that a fitted value has been generated for each observation.
When to use the adjust command in Stata?
When you use the adjust command without specifying any variables, it simply summarizes the linear predictions of the regression by rep78. Suppose that instead I typed For two of the independent variables in our regression, weight and length, adjust did nothing; it left them as is.
What does foreign equal to in Stata predict and adjust?
On the other hand, one could interpret the results with foreign equal to 0.304 as pertaining to a car that contains 70% domestic parts and 30% foreign parts. Whether to force a dummy variable to remain 0 or 1 when forming predictions depends entirely on the context of the model.
How is adjust used in predict and adjust?
However, in computing the linear prediction of mpg, adjust did not use the actual values of foreign that are in the dataset. Instead, it computed the prediction, pretending that the value of foreign was 0.30434781 for every observation in the dataset.