Closer analysis revealed that there are few definitive studies. Those that do exist arrive at somewhat different conclusions. The Gunderson study compared private sector contract negotiations involving 500 or more workers from 1967 to March 1993. The authors acknowledge however, that their conclusions are based only on a comparison with Quebec. Varying Vulnerability of Employers Employers are unequally vulnerable to a prohibition on replacement workers.
Some employers are vastly more susceptible to competition from non-union competitors.
Other employers have a capital plant that requires regular maintenance even during a shutdown. Some can stockpile or reorganize during a shutdown, while others cannot. This alters the power balance and can thus skew wage settlements in different ways for different workplaces. The impact of a prohibition on employing replacement workers would therefore be quite uneven. Some argue that the laws should prohibit replacement workers because so few employers use them anyway.