Is there any reason why we should believe the manipulation of this rate only began in 2005? No reason whatsoever. Could it have begun in 2003? 2001? 1998? 1995? Well, how about 1991? Why not 1991? Yes, 1991. Really? Yep, the year 1991, a full 21 years ago.
In 1991, I had live trading screens that showed the Libor rates. In September of that year, on the third Wednesday, at 11 o’clock, I watched those screens to see where the futures contract should settle. Shortly afterwards, Liffe announced the contract settlement rate. Its rate was different from what had been shown on my screens, by a few hundredths of a per cent.
Simply put, then, it seems the misreporting of Libor rates may have been common practice since at least 1991. Although the difference between the reported rate and the actual rate might seem small, the total amount of money involved is material, given that Libor rates affect contracts worth hundreds of trillions. Also important is what such misreporting says about the culture of finance.
During 1991, at the London office of Morgan Stanley, the head of interest rate trading was a person who has been at the centre of the current scandal: Bob Diamond. I do not recall discussing Libor misreporting with Mr Diamond but since the misreporting was common knowledge among traders, I presume he was aware. (That, however, is not a criticism of Mr Diamond: what could he have done about this?)
There have been two distinct motivations for banks to misreport Libor rates. One motivation is discussed above: to directly increase profits. The other motivation arose during the 2008 financial crisis: to mask liquidity problems.