This Stata FAQ shows how to check if a dataset has duplicate observations.  There are two methods available for this task.  The first example will use commands available in base…
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Stata FAQ: How can I convert string variables to numeric variables in Stata? The easiest way to convert string variables to numeric form is to use the encode command. If…
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Converting dates entered as strings into numeric dates that can be used by Stata is relatively simple. The commands vary somewhat based on the format in which the data were…
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A single model may contain a number of linear equations. In such a model it is often unrealistic to expect that the equation errors would be uncorrelated. A set of…
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Here is a tiny example showing how to use the survey commands in Stata.  Consider the data file we call svysmall shown below. use https://stats.idre.ucla.edu/stat/stata/faq/svysmall, clear list house eth wt y…
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The examples below use Stata 7 or 8.  If you are using Stata version 9, please see this page. Here is a tiny example showing how to use the survey…
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When using survey data, the mean of a variable is calculated as the total (sum of the values) for that variable divided by the population size (the total number of…
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NOTE: If you want to see the design effect or the misspecification effect, use estat effects after the command. This example is taken from Levy and Lemeshow’s Sampling of Populations….
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The examples below use Stata 8.  If you are using Stata version 9, please see this page. This example is taken from Levy and Lemeshow’s Sampling of Populations. page 247…
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NOTE:  If you want to see the design effect or the misspecification effect, use estat effects after the command. This example is taken from Levy and Lemeshow’s Sampling of Populations,…
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