We prospect researchers say it all the time. But I’m not sure that our fundraising colleagues really get it.

It’s immeasurable. No, we cannot give you a precise figure.

An individual’s wealth is a private affair. Just how private is being made clear by the Panama Papers. Here we can see how people from footballers to political leaders hide their wealth and their income from public view. These are just the types of people that we prospect researchers are asked to analyse and measure; what is her wealth, and what is her gift capacity?

Bear in mind that Mossack Fonseca is described as Panama’s fourth largest firm in this offshore business. The Legal 500 lists five more leading firms operating in this sector in Panama. There are hundreds more in Panama, and more in the British Virgin Islands, Cayman, Gibraltar and any number of other fiscal watering holes. We are seeing, even with the 2.9 terabytes of information from Panama, only a tiny slice of the full picture.

The OECD reports that 27 of the 34 OECD members “store or require insufficient beneficial ownership information for legal persons, and no country is fully compliant with the beneficial ownership recommendations for legal arrangements.” In other words, as campaigners such as Andy Wightman have shown in his books on land ownership in Scotland, we cannot know who owns companies or who controls trusts.

The UK is rolling out regulations that will expose some of this – although information on the control of trusts (not the charitable sort, these are legal trusts) will only be available to ‘competent authorities.’ A grey phrase that, we can assume, excludes the, er, incompetent public. Business shareholdings of 25% or more will mean a declaration of beneficial ownership. It is worth noting that many of the schemes outlined in the Panama Papers involve small but valuable shareholdings. As Jake Hayman has already noted in Forbes, this is relevant to philanthropy.

The Panama Papers have many implications for prospect researchers. They are another mine of information – you will have to decide for yourself whether this is good practice, or not – on wealth. They remind us that we must be cautious with our estimates of wealth and gift capacity. And they demonstrate that our due diligence is less than comprehensive; if we cannot know who controls a business that wants to donate to us, or we cannot say  which companies Samantha Supporter controls, then how can we measure whether she meets our due diligence requirement?

I suggest sticking this version of The Panama Papers on the door of the Prospect Research office in your organisation:

1. No, we can’t tell you how wealthy she is
2. No, we can’t tell you who owns that property
3. Don’t expect due diligence to be really diligent. We’ll do our best, but don’t ask us to hack any more Panama lawyers.