StatLab Articles

Stata Basics: Combine Data (Append and Merge)

When I first started working with data, which was in a statistics class, we mostly used clean and completed dataset as examples. Later on, I realize it’s not always the case when doing research or data analysis for other purposes; in reality, we often need to put two or more dataset together to be able […]

Stata Basics: Subset Data

Sometimes only parts of a dataset mean something to you. In this post, we show you how to subset a dataset in Stata, by variables or by observations. We use the census.dta dataset installed with Stata as the sample data. Subset by variables * Load the data > sysuse census.dta (1980 Census data by state) […]

Stata Basics: Create, Recode and Label Variables

This post demonstrates how to create new variables, recode existing variables and label variables and values of variables. We use variables of the census.dta data come with Stata as examples. -generate-: create variables Here we use the -generate- command to create a new variable representing population younger than 18 years old. We do so by […]

Stata Basics: Data Import, Use and Export

In Stata, the very first step of analyzing a dataset, or do anything about it, should be opening the dataset in Stata so that it knows which file you are going to work with. Yes, you can simply double click on a Stata data file ends in .dta to open it, or you can do […]

Using Data.gov APIs in R

Data.gov catalogs government data and makes them available on the web; you can find data in a variety of topics such as agriculture, business, climate, education, energy, finance, public safty and many more. It is a good start point for finding data if you don’t already know which particular data source to begin your search, […]

Getting UN Comtrade Data with R

The UN Comtrade Database provides free access to global trade data. You can get data by using their data extraction interface or using their API to do so. In this post, we share some possible ways of downloading, preparing and plotting trade data in R. Before running this script, you’ll need to install the rjson […]

Look People are Going to Think… (Debate Rhetoric Redux)

I’m still looking at the rhetoric from the presidential debates, this time focusing on the first general election debate between Hillary Clinton and Donald Trump. I turned the data frame from last week into a corpus, did some pre-processing with the tm package (remove capitalization, punctuation, stopwords, stemming the words and then completing stems with […]

Using Census Data API with R

Datasets provided by the US Census Bureau, such as Decennial Census and American Community Survey (ACS), are widely used by many researchers, among others. You can certainly find and download census data from the Census Bureau website, from our licensed data source Social Explorer, or other free sources such as IPUMS-USA, then load the data […]

Debate Prep!

I’m teaching a Text as Data short course (using R) right now, and as a card-carrying political scientist, I couldn’t resist using the ongoing campaign as an example (this was, in party, a way of handling my own anxiety about last Monday’s debate — this is what I was doing while watching). So here goes… […]

A tidyr Tutorial

The tidyr package by Hadley Wickham centers on two functions: gather and spread. If you have struggled to understand what exactly these two functions do, this tutorial is for you. To begin we need to wrap our heads around the idea of “key-value pairs”. The help pages for gather and spread use this terminology to […]