These maps show the corporate networks of the top six banks in the USA. Each dot represents a company, and each line shows where a company controls another company. A "corporate network", therefore, is a network of control, with a single corporation at the top of the tree, ultimately controlling all the companies beneath it.
We have grouped together companies that are in the same country, in the shape of that country. This gives you an idea of the size of the corporate network, and how it is structured. By comparing different corporate networks, you can see where and how different companies operate.
Note that the position of the dots within a country is random.
OpenCorporates is building the world's first Open Data repository of corporate network information. We've started with the best-quality and most complete sources of data, such as the Federal Reserve's National Information Center, which requires banks to submit information about their control structures. As a bonus, banks and other financial institutions have some of the most interesting and complex corporate structures.
The definition of "control" turns out to be quite complex. The simplest definition of control is a simple majority shareholding (of more than 50% of voting shares in a company). However, the ways a company can exercise control over another company are much more complicated than that. Minority shareholders can still extert power, and control can also be exercised through contractual arrangements. We use the Federal Reserve's definition of control as defined in Form FR Y-10.
There are many reasons why a company might locate parts of its network abroad. For example, a company might locate a subsidiary in the Cayman Islands, because they operate a bank there. On the other hand, subsidiaries are often "shell companies", which don't carry out business in that jurisdiction, and exist only as an intermediary in a network. The reason you might want an intermediary in the Cayman Islands is to take advantage of their very low tax rates, or to make use of the fact that they allow you to keep many facts about your company a secret. We think it's interesting to see the proportion of a corporation's network that is based in tax havens. We have used ActionAid's list of tax havens for this purpose.
The truthful answer is, we don't know. What makes OpenCorporates' data unique is that every single fact comes with a provenance, showing where we got the data from, so you can make your own mind up about its accuracy. We also provide a metric of confidence in each fact.
Inaccuracies come in several different ways. We try to only use official sources of data - for example, the Federal Reserve obligates a corporation to register data. When we use unofficial sources (rarely), we assign them very low confidences and don't include them in our standard data views.
However, companies may have made mistakes in their reporting; the registry (in this case, the Federal Reserve) may have made a mistake in their recording or presentation of the data; we may have made mistakes in transcribing the data.
On these maps, you can find the sources for the data by following the link to the selected company at the top of the map. This takes you to the company network page on OpenCorporates. On that page, click on a dot representing a company, and then select "View sources for this information".
These maps are part of an ongoing project by OpenCorporates to create and visualise corporate networks using only fully sourced, Open Data. This particular visualisation was conceived and implemented by Kiln.