Diversity of international unions

As labour law is very diverse in different countries, so is the function of unions. For instance, in Germany only open shops are legal; that is, all discrimination based on union membership is forbidden. This affects the function and services of the union. In addition, German unions have played a greater role in management decisions through participation in corporate boards and co-determination than have unions in the United States. (newsletter/files/BTS012EN_12-15.pdf}.

In addition, unions' relations with political parties vary. In many countries unions are tightly bonded, or even share leadership, with a political party intended to represent the interests of working people. Typically this is a left-wing or socialist party, but many exceptions exist.

In the United States, by contrast, although it is historically aligned with the Democratic Party, the labour movement is by no means monolithic on that point; the International Brotherhood of Teamsters has supported Republican Party candidates on a number of occasions and the Professional Air Traffic Controllers Organization (PATCO) endorsed Ronald Reagan in 1980 (the following year, Reagan effectively destroyed PATCO, breaking a strike by bringing in permanent replacement workers).

The AFL-CIO has been against liberalising abortion, consistent with a Republican position, so as not to alienate its large Catholic constituency. In Britain the labour movement's relationship with the Labour Party is fraying as party leadership embarks on privatisation plans at odds with what some perceive as workers' interests.

In Western Europe, professional associations often carry out the functions of a trade union. Notable cases of these are the German Verein deutscher Ingenieure. In these cases, they may be negotiating for white collar workers, such as physicians, engineers or teachers. Typically such trade unions refrain from politics or pursue markedly more right-wing politics than their blue-collar counterparts [citation needed].

Finally, the structure of employment laws affects unions' roles and how they carry out their business. In many western European countries wages and benefits are largely set by governmental action. The United States takes a more laissez-faire approach, setting some minimum standards but leaving most workers' wages and benefits to collective bargaining and market forces.

Historically, the Republic of Korea has regulated collective bargaining by requiring employers to participate but collective bargaining has been legal only if held in sessions before the lunar new year. In totalitarian regimes such as Nazi-Germany and the Soviet Union, unions have typically been de facto government agencies devoted to smooth and efficient operation of enterprises.