Identifying circular ownership in BODS data

[StephenAbbott]

Circular ownership structures involve two or more legal vehicles directly or indirectly owning each other. In the UK, this is banned due to the risks.

In 2019, Global Witness found that 0.01% of companies registered in UK in 2019 were involved in circular ownership schemes, thus violating UK law (see Getting the UK's house in order report).

How can we best identify circular ownership in BODS data and provide an up-to-date query showing the number of companies which might exhibit circular ownership? See https://github.com/Global-Witness/uk-beneficial-ownership-analysis-2019-public