Collective bargaining has also had an impact on forms of wage improvement. It has focused in particular on the parts of working and employment conditions which, by their nature, must be regulated collectively. These include working hours. The extension of ancillary benefits, such as insurance and pensions, paid by the employer, also reflected pressure from trade unions. Only one in three OECD employees has wages agreed by collective agreement. The 36-member Organisation for Economic Co-operation and Development has become a strong supporter of collective bargaining to ensure that falling unemployment also leads to higher wages.  The term “collective bargaining” was first used in 1891 by Beatrice Webb, a founder of industrial relations in the United Kingdom.  It refers to the type of collective bargaining and agreements that existed since the rise of trade unions in the eighteenth century. In the United States, the National Labor Relations Act (1935) covers most collective agreements in the private sector. The Act makes it illegal for employers to discriminate, spy, harass or terminate workers because of their union membership, or to retaliate against them because they participate in campaigns or other “concerted activities”, form company unions or refuse to negotiate collective agreements with the union representing their employees. It is also illegal to require any employee to join a union as a condition of employment.
 Trade unions are also able to guarantee safe working conditions and fair remuneration for their work. A first effect of the extension of collective bargaining has been to reduce the wage gap between wages received at a given time by a given working group in different regions and in different companies in the same region, and even between one worker and another between the same employer. Trade unions initially had to accept the dominant regional differences, but their pressure to address the lower-paid regions reinforced the effect of improved communication and information in order to significantly reduce these differences, especially since the Second World War. . . .