“Follow the money”. It’s a cliché of investigative journalism for a very good reason. If you want to get to the heart of what is really going on, knowing who has paid what to whom frequently exposes the real action being hidden away behind warm words, evasive statements and muttered “no comments”.

It is also at the heart of many a public inquiry. Want to know why something happened? Who pays whom is again right at the centre of the story. Whether it is understanding drugs policy and the economics of the illegal market or looking at problems of rail safety, following the money reveals the systematic features that shape the behaviour being probed. Understand the financial incentives and you understand a large part of what is going on.

But there’s an exception.

Step forward, Lord Leveson and his inquiry. Many people being asked for their views. But the inquiry isn’t following the money.

Instead, it is studiously ignoring the money. For where are the advertisers, the sellers or the  purchasers of newspapers?

When you buy a newspaper, sell a newspaper or place an advert, you’re funding journalism. You may be funding a brave investigator unearthing corruption. Or a sordid fly-by-night who bullies, lies and intimidates. Either way, it is your cash transaction that is keeping them in business.

So why in this inquiry should those doing the funding get a free pass and not have their own behaviour looked at? After all, we know from the few occasions when people do withhold their money how quickly even mighty multinationals react.

Some stories do not betray their unpleasant sources and disreputable tactics when they appear in print. But plenty do.

And if newsagents are happy to still sell them, advertisers still happy to have their words appear next to them and the public still happy to buy them, is it any wonder the stories have been so widespread for so long?