"Economic value" is a slippery concept.

First off, most people read that as "price times volume", or the exchange value of some good or service. The Amazon River isn't exchanged, it has no exchange value.

Another definition of "economic value" is use value, which is to say, the benefit derived from use, possession, existence, control, etc., of some good. The problem here is that economics has little handle on estimating just what this use-value is. Some economists claim it cannot be measured or known (e.g., Ludwig von Mises), others note that it's not intrinsic but is always relative -- a property between the valuer and the valued (William Foster Lloyd in his 1834 essay on value, William Stanley Jevons in his book on money and transactions). That is, there is no absolute value.

(Lloyd's essay is prescient in some ways of Einstein's later work.)

Edwin Cannen, editor and researcher on Adam Smith notes that Smith's definition of wealth, "the annual labour and produce of the nation", specifically excludes the concept of land or mineral wealth as included in that definition. That's a recent discovery of mine in the past week or so, and I want to look into it further, but it's quite the observation.

I've been working on a couple of concepts. One is that there are really three related but distinct concepts: costs, value, and price. They're somewhat related, but through a loose mechanism.

Cost is what you give up to get something. "All costs are opportunity costs" (Krugman, Economics, 2008).

Value is what you gain by something. Individually, value is hard to measure but in aggregate you've got good percentage going off biological or ecological measures, usually of metabolism, energy, or energy-and-materials throughput.

Price then becomes a somewhat odd duck, in that it's a cost for the motivation of exchange. Ideally we'd like C <= P < V, that is, cost is less than or equal to price, which is less than value.

Several problems introduce themselves though, and I'm going to hand wave and say "it's complicated", but for numerous reasons over the short term, price can fall well below long-term costs (the rational is similar to the logic of the shut-down point in microeconomics).

But let's go back to the cost of providing Amazon, Inc., vs. the Amazon River.

The former has an economic throughput of, very roughly, $100 billion dollars. This is an estimate, and I think I'm high here. But there's a point to this.

Turns out if you look at US GDP and energy inputs, a barrel of oil generates about $1,000 of GDP. So Amazon's revenues represent about 1 million barrels of oil energy equivalent.

I'm going to estimate that the Amazon River Basin is about 1/4 the surface area of South America (which I've got as a constant in GNU Units). It receives incident sunlight at roughly 1 kW/m^2 for 8 hours a day, or equivalently, for 1/3 of the duration of a year.

In barrels of oil equivalent, that's about 7 trillion.

Which is to say, there's about 7 billion times the cost to provisioning the Amazon as there Amazon, Inc.

If Amazon, Inc. disappeared off the face of the Earth, a few tens of thousands of people would need to find a new job, and a few hundreds of millions others would have to travel to the store or find a new eCommerce provider.

If the Amazon disappeared off the face of the Earth, odds are that an event significant enough to destroy all of modern civilisation would have transpired. One valuation of that is the roughly $70 trillion of the global economy.

I'd say the river wins over Big River Book Company.

The fact that our economic system fails to account for the relative values correctly says far more for what's wrong with our economic system than with how valuable Amazon, Inc. is, or how unvaluable the Amazon River is.

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And checking my estimates. The Amazon River basin is 7 million km^2, or about 39% the area of South America.

Amazon's 2015 annual revenues were actually $107 billion, though profits were $1 billion. So I was less generous than intended.

Still, at 7 billion : 1 I'd argue my analysis is within reason.