How are subsidiaries of an organization defined?

We have not yet defined a subsidiary using a formal legal or financial definition. Currently, we attempt to identify parent companies by linking an organization to its "parent" entity in the graph. We are using SEC filings as our primary source. Example.

A parent company is identified in the Organization entity via the parentCompany attribute.

Here's how you might find all Organizations with parent companies in the Knowledge Graph:

type:Organization has:parentCompany

Because the parentCompany field is linked to the actual entity record of the parent company, you can also run more interesting searches such as this one, which identifies all companies with a publicly-traded parent company:

type:Organization parentCompany.isPublic:true