LAST week, the Nobel prize in economics was awarded to Jean Tirole (see this week's Free exchange column) for his work examining the difficulties in regulating firms with substantial market power. Mr Tirole's research is as relevant as ever, thanks to growing concern over the weight tech titans are throwing around in their corners of the economy. Paul Krugman does not mince words in summing up a widespread view of one particular internet behemoth:

Amazon.com, the giant online retailer, has too much power, and it uses that power in ways that hurt America.

The context is an ongoing dispute between Amazon and Hachette, a major book publisher. Publishers unhappy with Amazon's pricing of e-books have sought to change the pricing model for such works, and retain for themselves the ability to set a minimum price. When Amazon was unable to strike an acceptable agreement on pricing with Hachette, it began playing hardball, refusing to keep extra inventory of some Hachette print books in stock and delaying their shipping times. That, in turn, has prompted charges that Amazon is abusing its market power and should be subject to anti-trust action.

But what sort of market power does Amazon have? Mr Krugman reckons Amazon is a monopsonist: a firm big enough within its market to set pricing terms to its suppliers. It is using that power, he says, to relentlessly squeeze publishers. One might ask who (apart from publishers) cares. If suppliers are squeezed and the savings are passed on to consumers that seems like a grand thing. Mr Krugman's response is that Amazon cannot be trusted not to use its influence for malign ends: like systematically disadvantaging books with a particular political bent.

Amazon's behaviour in this case is certainly nasty and possibly unethical. Joshua Gans says it may also prove bad for business, even if the regulators do not seize the opportunity to crack down on the firm. But the suggestion that Amazon is a hulking monopsonist looks overstated to me.

What, for instance, is the source of Amazon's market power? Many critics argue that it is a function of its near monopoly in book sales. And it is true that Amazon handles a sizable minority of print sales and well over half of e-book sales. On the other hand, it is incredibly easy to go around Amazon. One of the works Amazon is supposedly dooming, according to Mr Krugman, is a book called "Sons of Wichita". But if one googles "Sons of Wichita", then one of the first results is the book's page at the website of Barnes & Noble, a rival online bookseller. Barnes & Noble offers a competitive price and 24-hour delivery (same day delivery in Manhattan!).

For that matter, it's not clear why Amazon should be considered a monopsony at all. Setting up online stores is not rocket science, after all. Many firms in many businesses sell their products directly to consumers. Why don't publishers? There may be one Amazon but there are billions of readers.

The answer, according to Mr Krugman, is that Amazon is not really in the bookselling business at all; it's in the buzz business:

Book sales depend crucially on buzz and word of mouth (which is why authors are often sent on grueling book tours); you buy a book because you’ve heard about it, because other people are reading it, because it’s a topic of conversation, because it’s made the best-seller list. And what Amazon possesses is the power to kill the buzz. It’s definitely possible, with some extra effort, to buy a book you’ve heard about even if Amazon doesn’t carry it — but if Amazon doesn’t carry that book, you’re much less likely to hear about it in the first place.

And this, I think, is where the argument against Amazon really falls apart, for a few reasons. One is that Amazon isn't delisting the books from Hachette; the "Sons of Wichita" page is still there, complete with user ratings and reviews. Another is that, if one buys Mr Krugman's argument, Amazon is providing booksellers with an extraordinarily valuable service (or another extraordinarily valuable service in addition to market research and logistics management) and should be able to demand its premium from publishers.

But the biggest reason is that one simply cannot argue with any credibility that Amazon has control over the market for buzz. My book buying habits may not be representative of the public at large, but while I almost always buy my books through Amazon I cannot remember the last time I discovered one there. I learn about books from blogs, from Twitter, from reviews in newspapers and magazines, from conversations with friends, from Oprah: all sorts of places. Then I google them, click on the Amazon page, and buy them. If the book is out of stock at Amazon, then I hit the back button and go to the next link down.

If the concern is that Amazon's tactics will make it hard to find out about interesting books, then there is no concern. If publishers cannot figure out how to do what so many other retailers of so many other different types of good are doing, then they probably deserve to go; no firm is owed a profitable business. And if Amazon acts in ever nastier fashion, then more people will go to the next link down.

The digital economy does present some very tricky market power questions, and regulators will have their hands full in coming decades managing them. Probably best for them to stay out of this battle for now.