## How do you change the reference group in Stata?

If you are using Stata 11, you can get rid of the xi: prefix and specify the omitted group like this… logit foreign ib4. rep78 and the fourth group is the omitted group. The -fvset- command can be used to permanently change the reference group (like the -char- command).

**What is the difference between Stata SE and MP?**

Stata MP is the fastest version of Stata and supports multicore/multiprocessor computers with parallel computing/processing of your analysis. Stata SE is for large datasets. Stata BE is for mid-sized datasets.

**Is the reference group 1 or 0?**

The group with all zeros is known as the reference group, which in our example is group 4. We will see exactly what this means after we look at the regression analysis results. With dummy coding the constant is equal to the mean of the reference group, i.e., the group with all dummy variables equal to zero.

### How do I choose a reference category?

Strategies for Choosing the Reference Category in Dummy Coding

- Strategy 1: Use the normative category. In many cases, the most logical or important comparisons are to the most normative group.
- Strategy 2: Use the largest category.
- Strategy 3: Use the category whose mean is in the middle, or conversely, at one of the ends.

**What is the reference group in regression?**

The value of the categorical variable that is not represented explicitly by a dummy variable is called the reference group. In this example, the reference group consists of Independent voters. In analysis, each dummy variable is compared with the reference group.

**How much faster is Stata MP?**

Stata/MP is the fastest and largest edition of Stata. On dual-core chips, Stata/MP runs 40% faster overall and 72% faster where it matters, on the time-consuming estimation commands. With more than two cores or processors, Stata/MP is even faster.

## What is the Egen command in Stata?

The Stata command egen, which stands for extended generation, is used to create variables that require some additional function in order to be generated. Examples of these function include taking the mean, discretizing a continuous variable, and counting how many from a set of variables have missing values.

**How do I choose a reference group?**