How we’ve crunched MPs data

There’s no master list of properties owned by MPs. The closest thing is the register of interests, in which they are required by Parliament’s standing orders to mention properties in which they have ‘‘a legal interest’’. This can mean several things. The most common is outright ownership. Another is if they are a beneficiary of a trust that owns property: In these cases, they do not legally own the property – the trustees do – but they have a beneficial interest. Around a dozen MPs disclosed property interests through such arrangements, totalling about $34m.

Several MPs have controlling interests in companies that own property. And two MPs – David Seymour and Nicola Willis – are discretionary beneficiaries of trusts that own property. Unlike a regular beneficiary, this means they may inherit the trust’s assets, but only if the trustees decide to include them.

These nuances make cataloguing Parliament’s property interests a difficult exercise.

An MP who may, at some undetermined point, inherit property is obviously not in the same financial position as one who currently owns many properties outright. An MP who will definitely inherit property owned by a family trust is also a step removed from outright ownership, as they don’t know when that will happen.

Where possible, we have noted these distinctions. The only MP for which the data definitely requires an asterisk is David Seymour, who owns no property himself but is a discretionary beneficiary of several properties.

To further complicate things, some MPs serve as trustees, but not beneficiaries, of trusts that own property. This means they own the property on paper, but have no beneficial interest in it – they’re basically managing the assets on another’s behalf.

To simplify all this, we have followed the definitions used in Parliament’s standing orders. Therefore, our data includes any property in which the MP has a legal interest, but excludes any property they control as a trustee.

Not all properties noted in the register could be found. This likely means it is owned in someone else’s name (say, a partner or relative). A few properties are overseas. In these cases, the existence of the property is noted, but no value can be assigned.

Some properties do not appear in the register of interests because they were bought after the register was filed. This only matters when it comes to calculating capital gains. When doing so, we have used the purchase price of the property, not the property’s value before it was bought by the MP. (An illustrative example: One MP bought a Wellington property at the end of June 2021. The capital gain, in our calculations, is $0, but the property itself went up in value by $110,000 in a year).

Conversely, some properties in the register have since been sold. We have included them but used the sale price of the property to calculate capital gain (meaning any value accrued since it was sold is not counted).

Several MPs have interests in Ma¯ori land blocks. These were excluded because the interests are usually fractional and have little economic value.