The excess of wages of workers in unionized firms over those of workers with similar skill levels in non-unionized firms. A positive differential is prima facie evidence that unions are beneficial for their members.
科学参考收录了60776条科技类词条，基本涵盖了常见科技类参考文献及英语词汇的翻译，是科学学习和研究的有利工具。