This paper by Guy and Scott argues that new information and communication technologies have been ‘power- biased’: they have allowed firms to monitor low-skill workers more closely, thus reducing the power of these workers. An efficiency wage model shows that ‘power-biased technical change’ in this sense may generate rising wage inequality accompanied by an increase in both the effort and unemployment of low-skill workers. The skill-biased technological change hypothesis, on the other hand, offers no explanation for the observed increase in effort.