Senator Herb Kohl (D-WI), chairman of the Senate Antitrust Subcommittee, has asked U.S. carriers to justify their SMS fees in an open letter. Calling on the CEOs of Verizon Wireless, AT&T, Sprint, and T-Mobile, Kohl states: “I specifically ask each of your companies to explain why text messaging rates have dramatically increased in recent years.”

Kohl wonders why the cost of text messages has increased 100% over the last 3 years, while SMS files remain small and inexpensive to transmit. He postulates that the four major U.S. carriers, serving over 90% of the country’s subscribers, may be increasing prices due to decreased competition.

The Senator has asked all four companies to justify the 100% SMS rate, provide data on text message use, submit a comparison of prices for other services over the same period (voice, email, data, etc.), and also explain how their SMS pricing structure might differ from the other carriers.

Though none of the industry giants have responded as of yet (the letter was published on September 9th), Kohl has asked for the information to be delivered by October 6th.

[Via AlleyInsider]