Sorry that November has been another crummy month for posts. Here’s one that I’ve been meaning to write for quite awhile.
While there is a lot of free GIS data out there, one of the black holes is business data. Specifically, if you want to plot all of the businesses in one industry or all of the branches or locations of one company, where do you get the data? I’ve found that, if you need a comprehensive resource, this is one of those datasets that you have to pay for.
At our library we subscribe to a great business directory called ReferenceUSA, which is produced by company called InfoUSA. Their directories of American and Canadian businesses are extremely comprehensive and cover every business large an small. They also have an international directory that has mid-size to large businesses. You can generate lists of businesses using several criteria and filters.
For places, you can specify the entire country, states, counties, places, or ZIP codes. You can get generate lists based on company names, keywords, or NAICS codes to grab all of the businesses in one industry. Once you have your list, you can click on each individual business to get a detailed profile. For GIS purposes, you’ll want to use the download option. Depending on your subscription, you’ll be able to download only a certain number of records at a time (we can get 25 records per download). Just download as a csv file, save, open in a spreadsheet, then start downloading subsequent batches and start copying and pasting records in a master file.
When you go to download, you’ll be prompted to choose basic, detailed, or custom. Basic isn’t going to cut it, as it’s missing the key fields – latitude and longitude coordinates. Choose the detailed option to get all of the fields. The custom option has some bugs – you’ll get lat and long without decimal places and some of the data for fields will be missing. Once you have all of the detailed records, you can delete a lot of the unecessary fields. You’ll want to, as many of the field headings are not database friendly – many are long and contain spaces, which will cause problems when you go to import the table into GIS. So be sure to delete any that you don’t need and fix the ones you do need.
Once you have your table ready, add it to your favorite GIS program. In ArcGIS you can use the Add XY Table feature to plot the points and turn them into a shapefile. Remember to specify the X coordinate as your longitude field and the Y coordinate as latitude, and define your geographic coordinate system as WGS 84. Once you plot them, right click on the feature in the Table of Contents and export them out as a shapefile so you have a permanent layer (see my previous XY post for more details). You can map the businesses as regular old points, or make some graduated symbols based on some of the attributes, like sales or total employees (ReferenceUSA doesn’t provide the exact data, but identifies a range, i.e. 1 to 10 employees, 11 to 25, etc).
Most of the open source alternatives also have a tool or plugin that allow you to plot XY data. Of course, the data does include address fields if you wanted to geocode your points rather than plot XY (but plotting XY is a million times easier and doesn’t require downloading huge street network files).
The good news here is that if you’re not affiliated with a university, you can probably get access to this db from a large public library, as many will have a subscription to a business directory as a matter of course. If they don’t have RefUSA they may have an alternative like the D and B Million Dollar Database. It’s another business directory that allows you to download XY data for businesses, but it is not nearly as comprehensive.