MONOPSONY-BUSTING. The exclusive right to buy fish at a port looks like a valuable asset, particularly in light of the potential for hold-ups when the fisherman faces the choice of accepting the buyer's offer or risking the fish spoiling before he can land the fish at another port, where there might be another monopsonist. Michael Giberson at Knowledge Problem links to a Washington Post article that "delivers a fantastic story" about the role of information in mastering monopsony.

A convenience taken for granted in wealthy nations, the cellphone is putting cash in the pockets of people for whom a dollar is a good day's wage. And it has made market-savvy entrepreneurs out of sheepherders, rickshaw drivers and even the acrobatic men who shinny up palm trees to harvest coconuts here in Kerala state.

"This has changed the entire dynamics of communications and how they organize their lives," said C.K. Prahalad, an India-born business professor at the University of Michigan who has written extensively about how commerce -- and cellphones -- are used to combat poverty.

"One element of poverty is the lack of information," Prahalad said. "The cellphone gives poor people as much information as the middleman."

Transactions costs still matter, even if they're not a fashionable explanation in academic circles.

[Sardine fisherman Babu] Rajan said that before he got his first cellphone a few years ago, he used to arrive at port with a load of fish and hope for the best. The wholesaler on the dock knew that Rajan's un-iced catch wouldn't last long in the fiery Indian sun. So, Rajan said, he was forced to take whatever price was offered -- without having any idea whether dealers in the next port were offering twice as much.

Now he calls several ports while he's still at sea to find the best prices, playing the dealers against one another to drive up the price.

Markets exist to divide the gains from trade. Profits stemming from ignorance are being competed away, and the profiteers don't like it.

Rajan said the dealers don't necessarily like the new balance of power, but they are paying better prices to him and thousands of other fishermen who work this lush stretch of coastline. "They are forced to give us more money because there is competition," said Rajan, who estimated that his income has at least tripled to an average of $150 a month since 2000, when cellphones began booming in India. He said he is providing for his family in ways that his fisherman father never could, including a house with electricity and a television.

"When I was a kid we never had enough money for clothes and books, so we never really went to school," said Rajan, 50. "Now everything is different."

More evidence of the opportunity costs of ignorance. Information about the brokers' bid prices turns out to be more valuable than knowledge of the fishing grounds.