As is known, the United States of America is the only one of the leading industrial nations where employment grew substantially in the 1990s. Between 1991 and 2000 – the last year in which employment grew and unemployment decreased – the number of employed people increased in the USA by about 14.9 per cent, leading to a drop in the rate of unemployment from 7.5 to 4 per cent (Bureau of Labor Statistics 2002). Employment growth was accompanied in the first half of the 1990s by the flexibility of wages. Average gross hourly earnings in the private sector of the economy (excluding agriculture) decreased in real terms by 0.8 per cent between 1991 and 1995. It was not until 1997 that real gross hourly earnings reached the level registered in 1991. From the firms’ standpoint, the nominal cost of labour per unit of output grew by 6.8 per cent between 1991 and 1997, while the implicit deflator of value added increased by 12 per cent (Council of Economic Advisers 2001, 2002). The cost of labour per unit of output thus registered a decrease in real terms with respect to the beginning of the decade.