Introduction and background
It is often argued that the vitality of the Japanese employment system is sustained by personnel management rules and practices which make a clear distinction between the ‘core’ and the ‘non-core’ employees. The former, predominantly male, enjoy the privileges of long-term employment, wage increases and promotion based on age and length of service (nenko), and internal career progression through job rotation and in-company training; whereas the latter group is excluded (Galenson and Odaka 1976; Ishikawa 1980; Odaka 1984). Women workers constitute a high proportion of the latter category of employees. Their relatively low wages, high turnover and flexible entry and exit from the labour market play an especially important role in maintaining the flexibility of the employment system (Shinotsuka 1982; Kawashima 1987). Until very recently, direct exclusion and discr imination against women in all stages of employment was both legal and socially acceptable.