Geocode Addresses in Stata

Overview

geocode.ado is a Stata program designed to geocode addresses using the Nominatim API. It adds latitude and longitude coordinates to your dataset based on address information.

Requirements

• Stata with internet access
• jsonio package for handling JSON data
• curl command-line tool

Installation

1. Install the jsonio package:

   ssc install jsonio

2. Ensure curl is installed:

   • For Windows: Download and install from curl official website.
   • For macOS: Use Homebrew:

     brew install curl

   • For Linux: Use the package manager for your distribution (e.g., apt-get install curl for Debian-based systems).

3. Save the ADO file:

   • Save the geocode.ado script in your Stata ADO directory. You can find the directory by running adopath in Stata.

Usage

1. Load your dataset:

   use your_dataset.dta, clear

2. Run the geocode command:

   geocode address_var, save(geocoded_dataset.dta)

   • address_var: The variable in your dataset containing the addresses to be geocoded.
   • save(string): The name of the output dataset to save the geocoded data.

Example

* Load your dataset
use your_dataset.dta, clear

* Perform geocoding
geocode address, save(geocoded_dataset.dta)

Details

• The geocode program will create two new variables in your dataset: latitude and longitude.
• The program loops over each observation, sends the address to the Nominatim API, and parses the returned JSON response to extract latitude and longitude.
• The geocoded data is saved to the specified output file.

Notes

• Ensure compliance with Nominatim’s usage policy and rate limits.
• Consider adding delays between requests for large datasets to avoid hitting rate limits.
• Basic error handling is included; further enhancements can be made to handle various edge cases and improve robustness.

Support

For issues or questions, please contact the maintainer of this ADO file or consult Stata's online resources and forums for additional help.