What’s the safest investment as the global economy enters increasingly risky, troubled times? I’ve reviewed hundreds of academic papers, investment reports and newsletters and researched long-term strategies and backtests and reached one conclusion.

I won’t keep you in suspense: it’s bat guano (or seabird guano if you can’t get the bat stuff). Yes, bat doo-doo is the safest single investment on the planet.

OK, so I didn’t do a lot of fancy research because that would have been a waste of time. If the era we’re entering is fundamentally unlike the previous eras, then studying past investment results and strategies will generate dangerously misleading conclusions.

Here’s the thinking that leads to bat guano being the number one Safest Investment.

1. The safest investment must have permanent, substantial demand supporting the bid. People need to eat, and nowadays that means having access to high-quality, organic fertilizers like bat and seabird guano.

No matter what happens in the global economy, people will still need to eat and they will need fertilizer to grow enough food to avoid mass starvation. People will trade oil, gold, whatever they have of value for food, and while everybody knows about fresh water, good soil and oil to run the tractors and delivery vehicles, the essential role of wide-spectrum fertilizers is often unappreciated.

2. There can’t be super-cheap substitutes that are extracted/manufactured everywhere. You can get the various components of fertilizer from other sources, but bat/seabird guano is an excellent source of Nitrogen, Phosphorous, and Potash (Potassium), the essential N-P-K of fertilizers.

The sources for P and K are not all that abundant. In my view, there are no readily available dirt-cheap substitutes for bat guano.

3. An investment that can be gutted by financial rules changing overnight is not safe. If there’s one thing we know about real financial crises, it’s that the rules will change overnight, and keep on changing.