Niels Westergård-Nielsen has been member of several Danish Government Commissions on the labour Market and on Greenland, Chaired the Commission on Apprentices, 1993. The most recent commission was the wage commission.

He has authored various textbooks on the Danish Labour Market, authored scientific books and articles in leading journals on issues on skills and education, wages, health factors, HR, satisfaction, data issues and productivity. Has served as chairman of several research and evaluation committees: (evaluation of Uppsala University, Norwegian Research Council, EU-projects) and taken part in several large international research projects. The research started in labour market studies using register data (and was among the first doing that). This led to cooperation with psychiatrists and publications in the medical literature.

Niels then turned register research into research on what happens inside firms concerning personnel and firm performance. Keywords in this research: job turnover, job satisfaction, wage policies of firms, firm specific human capital, costs of job turnover, intergenerational mobility.