Mike, thanks for going to the trouble to provide such detailed and helpful comment. The Roodooryoku choosa figures for 2012 show a total number of employees in non-agricultural industries of 54.52 million, including
14.89 million in enterprises of 500+, 10.19 million in enterprises of 100-499, 8.48 m in enterprises of 30-99,
15.55 m in enterprises of below 30, and 4.95 million government employees. The total labour force is 65.55 m, including 2.85 m unemployed. So according to these figures, 22.7% of the workforce is employed in enterprises of 500+, and 7.5% are government employees
- following Ron Dore in British factory-Japanese factory, I tend to think that conditions working as a government employee are not too different to those working for a large firm - making 30.2%. Impossible to say from these figures how many work for firms employing between 300 and 500, but if one were to assume half of those employed in firms employing between 100 and 500, then it would be 5.85m, or 8.9%.
Adding that to 30.2% gives 39.1%. So to say that about one-third of Japanese workers work for a large firm seems about right, with another 7-8% working for government (including e.g. teachers, of course).

However, as we know, large firms are employing more non-regular workers than they used to.

Peter

Peter Cave
Lecturer in Japanese Studies
SALC, University of Manchester