On the other hand, from 1995 to 2000, the productivity growth rates of most European countries lagged that of both Canada and the United States; in a way, this is an indication of the rather satisfactory level of the Canadian performance at the time. [...] He found that most of the time, the stronger the perception of the competition, the higher the incentive to innovate, but there were exceptions. [...] The double question of joint effects between several productivity determinants and of the specificity of the combination of such determinants to one country is also echoed by Sharpe (2006) who studied the causes of the productivity resurgence in the United States and concluded that questions remain concerning how these factors came together to create the high productivity success since the mid-199 [...] As a general rule, the degree of competition is positively correlated with productivity: the higher the degree of competition, the higher the productivity growth. [...] But usually, there is also a link between labour market regulation and the level of employment: the higher the level of regulatory measures, the lower the employment level and, hence, the higher the productivity.