overall twothirds of nonregular workers are women data from business and labour force surveys since the s jilpt a indicate that an increasing proportion of employers cite reducing labour costs as the most important reason for hiring nonregular employees regardless of their particular category indeed firms can save wage and nonwage costs by paying workers less on an hourly basis eg in parttime workers were paid only of hourly wages of fulltime workers by paying lower or no bonuses and retirement allowances and by using current exemptions of certain worker categories from health pension and el contributions