Investigations cost money. The harder it is to find facts, the more you have to spend to figure out what’s going on. Is that why the fight against overseas bribery may be reaching a plateau?

I have long believed that most corruption cases prosecuted by the U.S. government are slam dunks that are comparatively cheap and easy to prove, often as a result of companies turning themselves in.

Now comes an article from the Washington Post that says the government relies on companies’ internal probes of corrupt practices, leaving much of the detective work to the very companies under suspicion.

A day after the Post article, the world’s main anti-corruption watchdog, Transparency International, sounded an alarm that corruption enforcement is stagnating across the developed world.

I don’t think developed countries have all of a sudden discovered that they like bribery of overseas officials. It’s just that budgets are no bigger than they ever were for the kind of plodding, meticulous fact gathering you need to investigate the conversations, emails and money flows needed to prove a criminal corruption case.

Instead, governments such as America’s have relied on companies turning themselves in, principally in the process of due diligence before a merger or acquisition. Lawyers looking over their books correctly calculate that if they discover evidence of bribery, turning the company in and negotiating a fine without jail time is preferable to having the crime discovered and punished more severely later on.

If anti corruption activity has stagnated, could it be that the dearth of M&A activity the last few years has meant fewer lawyers discovering fewer sins in their own back yards?

It’s an ugly truth, but finding evidence of corruption on a widespread basis costs a ton of money that companies sometimes have, but governments rarely do.