A trade union (or a labor union in the U.S.) is an association of workers forming a legal unit or legal personhood, usually called a "bargaining unit", which acts as bargaining agent and legal representative for a unit of employees in all matters of law or right arising from or in the administration of a collective agreement. Labour unions typically fund the formal organization, head office, and legal team functions of the labour union through regular fees or union dues. The delegate staff of the labour union representation in the workforce are made up of workplace volunteers who are appointed by members in democratic elections.

Today, unions are usually formed for the purpose of securing improvement in pay, benefits, working conditions, or social and political status through collective bargaining by the increased bargaining power wielded by the banding of the workers.^[1] The trade union, through an elected leadership and bargaining committee, bargains with the employer on behalf of union members (rank and file members) and negotiates labour contracts (collective bargaining) with employers. The most common purpose of these associations or unions is "maintaining or improving the conditions of their employment".^[2] This may include the negotiation of wages, work rules, complaint procedures, rules governing status of employees including promotions, just cause conditions for termination, and employment benefits.

Unions may organize a particular section of skilled workers (craft unionism),^[3] a cross-section of workers from various trades (general unionism), or attempt to organize all workers within a particular industry (industrial unionism). The agreements negotiated by a union are binding on the rank and file members and the employer and in some cases on other non-member workers. Trade unions traditionally have a constitution which details the governance of their bargaining unit and also have governance at various levels of government depending on the industry that binds them legally to their negotiations and functioning.

Originating in Great Britain, trade unions became popular in many countries during the Industrial Revolution. Trade unions may be composed of individual workers, professionals, past workers, students, apprentices or the unemployed. Trade union density, or the percentage of workers belonging to a trade union, is highest in the Nordic countries.^[4][5]

Since the publication of the History of Trade Unionism (1894) by Sidney and Beatrice Webb, the predominant historical view is that a trade union "is a continuous association on wage earners for the purpose of maintaining or improving the conditions of their employment."^[2] Karl Marx described trade unions thus: "The value of labour-power constitutes the conscious and explicit foundation of the trade unions, whose importance for the […] working class can scarcely be overestimated. The trade unions aim at nothing less than to prevent the reduction of wages below the level that is traditionally maintained in the various branches of industry. That is to say, they wish to prevent the price of labour-power from falling below its value" (Capital V1, 1867, p. 1069).

A modern definition by the Australian Bureau of Statistics states that a trade union is "an organization consisting predominantly of employees, the principal activities of which include the negotiation of rates of pay and conditions of employment for its members."^[6]

Yet historian R.A.

Leeson, in United we Stand (1971), said:

Recent historical research by Bob James in Craft, Trade or Mystery (2001) puts forward the view that trade unions are part of a broader movement of benefit societies, which includes medieval guilds, Freemasons, Oddfellows, friendly societies, and other fraternal organizations.

The 18th century economist Adam Smith noted the imbalance in the rights of workers in regards to owners (or "masters"). In The Wealth of Nations, Book I, chapter 8, Smith wrote:

As Smith noted, unions were illegal for many years in most countries, although Smith argued that it should remain illegal to fix wages or prices by employees or employers.

There were severe penalties for attempting to organize unions, up to and including execution.

Despite this, unions were formed and began to acquire political power, eventually resulting in a body of labour law that not only legalized organizing efforts, but codified the relationship between employers and those employees organized into unions.

The origins of trade unions can be traced back to 18th century Britain, where the rapid expansion of industrial society then taking place drew women, children, rural workers and immigrants into the work force in large numbers and in new roles. They encountered a large hostility in their early existence from employers and government groups; at the time, unions and unionists were regularly prosecuted under various restraint of trade and conspiracy statutes. This pool of unskilled and semi-skilled labour spontaneously organized in fits and starts throughout its beginnings,^[2] and would later be an important arena for the development of trade unions. Trade unions have sometimes been seen as successors to the guilds of medieval Europe, though the relationship between the two is disputed, as the masters of the guilds employed workers (apprentices and journeymen) who were not allowed to organize.^[7][8]

Trade unions and collective bargaining were outlawed from no later than the middle of the 14th century, when the Ordinance of Labourers was enacted in the Kingdom of England, but their way of thinking was the one that endured down the centuries, inspiring evolutions and advances in thinking which eventually gave workers their necessary rights. As collective bargaining and early worker unions grew with the onset of the Industrial Revolution, the government began to clamp down on what it saw as the danger of popular unrest at the time of the Napoleonic Wars. In 1799, the Combination Act was passed, which banned trade unions and collective bargaining by British workers. Although the unions were subject to often severe repression until 1824, they were already widespread in cities such as London. Workplace militancy had also manifested itself as Luddism and had been prominent in struggles such as the 1820 Rising in Scotland, in which 60,000 workers went on a general strike, which was soon crushed. Sympathy for the plight of the workers brought repeal of the acts in 1824, although the Combination Act 1825 severely restricted their activity.

By the 1810s, the first labour organizations to bring together workers of divergent occupations were formed.

Possibly the first such union was the General Union of Trades, also known as the Philanthropic Society, founded in 1818 in Manchester. The latter name was to hide the organization's real purpose in a time when trade unions were still illegal.^[9]

The first attempts at setting up a national general union were made in the 1820s and 30s. The National Association for the Protection of Labour was established in 1830 by John Doherty, after an apparently unsuccessful attempt to create a similar national presence with the National Union of Cotton-spinners. The Association quickly enrolled approximately 150 unions, consisting mostly of textile related unions, but also including mechanics, blacksmiths, and various others. Membership rose to between 10,000 and 20,000 individuals spread across the five counties of Lancashire, Cheshire, Derbyshire, Nottinghamshire and Leicestershire within a year. To establish awareness and legitimacy, the union started the weekly Voice of the People publication, having the declared intention "to unite the productive classes of the community in one common bond of union."

In 1834, the Welsh socialist Robert Owen established the Grand National Consolidated Trades Union. The organization attracted a range of socialists from Owenites to revolutionaries and played a part in the protests after the Tolpuddle Martyrs' case, but soon collapsed.

More permanent trade unions were established from the 1850s, better resourced but often less radical.

The London Trades Council was founded in 1860, and the Sheffield Outrages spurred the establishment of the Trades Union Congress in 1868, the first long-lived national trade union center. By this time, the existence and the demands of the trade unions were becoming accepted by liberal middle class opinion. In Principles of Political Economy (1871) John Stuart Mill wrote:

Trade unions were finally legalized in 1872, after a Royal Commission on Trade Unions

This period also saw the growth of trade unions in other industrializing countries, especially the United States, Germany and France.

In the United States, the first effective nationwide labour organization was the Knights of Labor, in 1869, which began to grow after 1880. Legalization occurred slowly as a result of a series of court decisions.^[11] The Federation of Organized Trades and Labor Unions began in 1881 as a federation of different unions that did not directly enrol workers. In 1886, it became known as the American Federation of Labor or AFL.

In Germany the Free Association of German Trade Unions was formed in 1897 after the conservative Anti-Socialist Laws of Chancellor Otto von Bismarck were repealed.

In France, labour organization was illegal until 1884.

The Bourse du Travail was founded in 1887 and merged with the Fédération nationale des syndicats (National Federation of Trade Unions) in 1895 to form the General Confederation of Labour (France).

The prevalence of unions in various countries can be measured by the concept of "union density", which is expressed as a percentage of the total number of workers in a given location who are trade union members.^[12] Trade union density around the world shows great variation.

Supporters of unions, such as the ACTU or Australian Labor Party (ALP), often credit trade unions with leading the labour movement in the early 20th century. This generally sought to end child labour practices, improve worker safety, increase wages for both union workers and non-union workers, raise the entire society's standard of living, reduce the hours in a work week, provide public education for children, and bring other benefits to working class families.^[13]

Melbourne Trades Hall was opened in 1859 with Trades and Labour Councils and Trades Halls opening in all cities and most regional towns in the next forty years. During the 1880s Trade unions developed among shearers, miners, and stevedores (wharf workers), but soon spread to cover almost all blue-collar jobs. Shortages of labour led to high wages for a prosperous skilled working class, whose unions demanded and got an eight-hour day and other benefits unheard of in Europe.

Australia gained a reputation as "the working man's paradise."

Some employers tried to undercut the unions by importing Chinese labour.

This produced a reaction which led to all the colonies restricting Chinese and other Asian immigration.

This was the foundation of the White Australia Policy. The "Australian compact", based around centralised industrial arbitration, a degree of government assistance particularly for primary industries, and White Australia, was to continue for many years before gradually dissolving in the second half of the 20th century.

In the 1870s and 1880s, the growing trade union movement began a series of protests against foreign labour. Their arguments were that Asians and Chinese took jobs away from white men, worked for "substandard" wages, lowered working conditions and refused unionisation.^[14]

Objections to these arguments came largely from wealthy land owners in rural areas.^[14] It was argued that without Asiatics to work in the tropical areas of the Northern Territory and Queensland, the area would have to be abandoned.^[15] Despite these objections to restricting immigration, between 1875 and 1888 all Australian colonies enacted legislation which excluded all further Chinese immigration.^[15] Asian immigrants already residing in the Australian colonies were not expelled and retained the same rights as their Anglo and Southern compatriots.

The Barton Government which came to power after the first elections to the Commonwealth parliament in 1901 was formed by the Protectionist Party with the support of the Australian Labor Party. The support of the Labor Party was contingent upon restricting non-white immigration, reflecting the attitudes of the Australian Workers Union and other labour organisations at the time, upon whose support the Labor Party was founded.

In the Baltic states trade unions were the part of the Soviet Union trade union system and closely connected with the party in the state. Industrial actions were not a part of their activities. After 1990 trade unions in the Baltic states have experienced rapid loss of membership and economic power, while employers’ organisations increased both power and membership. Low financial and organisational capacity caused by declining membership adds to the problem of interest definition, aggregation and protection in negotiations with employers’ and state organisations. Even the difference exists in the way of organization trade union and density. Starting from 2008 the union density slightly decrease in Latvia and Lithuania. In case of Estonia this indicator is lower than in Latvia and Lithuania but stays stable average 7 percent from total number of employment.^[16] Historical legitimacy is one of the negative factors that determine low associational power.^[17]

With 65% of the workers belonging to a union Belgium is a country with one of the highest percentages of labour union membership. Only the Scandinavian countries have a higher labour union density. The biggest union with around 1.7 million members is the Christian democrat Confederation of Christian Trade Unions (ACV-CSC) which was founded in 1904.^[18] The origins of the union can be traced back to the "Anti-Socialist Cotton Workers Union" that was founded in 1886.^[19] The second biggest union is the socialist General Federation of Belgian Labour (ABVV-FGTB) which has a membership of more than 1.5 million.^[20] The ABVV-FGTB traces its origins to 1857, when the first Belgian union was founded in Ghent by a group of weavers. The socialist union, in its current form, was founded in 1898. The third 'big' union in Belgium is the liberal General Confederation of Liberal Trade Unions of Belgium (ACLVB-CGSLB) which is relatively small in comparison to the first two with a little under 290 thousand members.^[21] The ACLVB-CGSLB was founded in 1920 in an effort to unite the many small liberal unions. Back then the liberal union was known as the "Nationale Centrale der Liberale Vakbonden van België". In 1930, the ACLVB-CGSLB adopted its current name.^[22]

Besides these "big three" there is a long list of smaller unions, some more influential than others.

These smaller unions tend to specialize in one profession or economic sector.

Next to these specialized unions there is also the Neutral and Independent Union that reject the pillarization that, according to them, the "big three" represent. There is also a small Flemish nationalist union that exists only in the Flemish-speaking part of Belgium, called the Vlaamse Solidaire Vakbond. The last Belgian union worth mentioning is the very small, but highly active anarchist union called the Vrije Bond.

Labour unions have existed in Canada since the early 1800s.

There is a record of skilled tradesmen in the Maritimes having a union organization during the War of 1812. Canadian unionism had early ties with Britain. Tradesmen who came from Britain brought traditions of the British trade union movement, and many British unions had branches in Canada. Canadian unionism ties with the United States eventually replaced those with Britain.

Collective bargaining was first recognized in 1945, after the strike by the United Auto Workers at the General Motors' plant in Oshawa, Ontario. Justice Ivan Rand issued a landmark legal decision after the strike in Windsor, Ontario, involving 17,000 Ford workers. He granted the union the compulsory check-off of union dues. Rand ruled that all workers in a bargaining unit benefit from a union-negotiated contract. Therefore, he reasoned they must pay union dues, although they do not have to join the union.

The post-World War II era also saw an increased pattern of unionization in the public service. Teachers, nurses, social workers, professors and cultural workers (those employed in museums, orchestras and art galleries) all sought private-sector collective bargaining rights. The Canadian Labour Congress was founded in 1956 as the national trade union center for Canada.

In the 1970s the federal government came under intense pressures to curtail labour cost and inflation.

In 1975, the Liberal government of Pierre Trudeau introduced mandatory price and wage controls. Under the new law, wages increases were monitored and those ruled to be unacceptably high were rolled back by the government.

Pressures on unions continued into the 1980s and '90s.

Private sector unions faced plant closures in many manufacturing industries and demands to reduce wages and increase productivity.

Public sector unions came under attack by federal and provincial governments as they attempted to reduce spending, reduce taxes and balance budgets.

Legislation was introduced in many jurisdictions reversing union collective bargaining rights, and many jobs were lost to contractors.^[23]

Prominent domestic unions in Canada include ACTRA, the Canadian Union of Postal Workers, the Canadian Union of Public Employees, the Public Service Alliance of Canada, the National Union of Public and General Employees, and Unifor. International unions active in Canada include the International Alliance of Theatrical Stage Employees, United Automobile Workers, United Food and Commercial Workers, and United Steelworkers.

Until around 1990 Colombian trade unions were among the strongest in Latin America.^[24] However, the 1980s expansion of paramilitarism in Colombia saw trade union leaders and members increasingly targeted for assassination, and as a result Colombia has been the most dangerous country in the world for trade unionists for several decades.^[25][26][27] Between 2000 and 2010 Colombia accounted for 63.12% of trade unionists murdered globally.^[28] According to the International Trade Union Confederation (ITUC) there were 2832 murders of trade unionists between 1 January 1986 and 30 April 2010,^[28] meaning that "on average, men and women trade unionists in Colombia have been killed at the rate of one every three days over the last 23 years."^[29]

In Costa Rica, trade unions first appeared in the late 1800s to support workers in a variety of urban and industrial jobs, such as railroad builders and craft tradesmen.^[30] After facing violent repression, such as during the 1934 United Fruit Strike, unions gained more power after the 1948 Costa Rican Civil War.^[30] Today, Costa Rican unions are strongest in the public sector, including the fields of education and medicine, but also have a strong presence in the agricultural sector.^[30] In general, Costa Rican unions support government regulation of the banking, medical, and education fields, as well as improved wages and working conditions.^[31]

Trade unions in Germany have a history reaching back to the German revolution in 1848, and still play an important role in the German economy and society. In 1875 the SPD, the Social Democratic Party of Germany, which is one of the biggest political parties in Germany, supported the forming of unions in Germany.^[32] The most important labour organisation is the German Confederation of Trade Unions (Deutscher Gewerkschaftsbund – DGB), which represents more than 6 million people (31 December 2011) and is the umbrella association of several single trade unions for special economic sectors. The DBG is not the only Union Organization that represents the working trade. There are smaller organizations, such as the CGB, which is a Christian-based confederation, that represent over 1.5 million people.^[33]

In India, the Trade Union movement is generally divided on political lines.

According to provisional statistics from the Ministry of Labour, trade unions had a combined membership of 24,601,589 in 2002.

As of 2008, there are 11 Central Trade Union Organisations (CTUO) recognized by the Ministry of Labour.^[34] The forming of these unions was a big deal in India.

It led to a big push for more regulatory laws which gave workers a lot more power.^[35]

A trade union with nearly 2,000,000 members is the Self Employed Women's Association (SEWA) which protects the rights of Indian women working in the informal economy.

In addition to the protection of rights, SEWA educates, mobilizes, finances, and exalts their members' trades.^[36] Multiple other organizations represent workers.

These organizations are formed upon different political groups.

These different groups allow different groups of people with different political views to join a Union.^[37]

Labour unions emerged in Japan in the second half of the Meiji period as the country underwent a period of rapid industrialization.^[38] Until 1945, however, the labour movement remained weak, impeded by lack of legal rights,^[39] anti-union legislation,^[38] management-organised factory councils, and political divisions between “cooperative” and radical unionists.^[40] In the immediate aftermath of the Second World War, the US Occupation authorities initially encouraged the formation of independent unions.^[39] Legislation was passed that enshrined the right to organise,^[41] and membership rapidly rose to 5 million by February 1947.^[39] The organisation rate, however, peaked at 55.8% in 1949 and subsequently declined to 18.2% (2006).^[42] The labour movement went through a process of reorganisation from 1987 to 1991^[43] from which emerged the present configuration of three major labour union federations, Rengo, Zenroren, and Zenrokyo, along with other smaller national union organisations.

Before the 1990s, unions in Mexico had been historically part of a state institutional system.

From 1940 until the 1980s, during the worldwide spread of neoliberalism through the Washington Consensus, the Mexican unions did not operate independently, but instead as part of a state institutional system, largely controlled by the ruling party.^[44]

During these 40 years, the primary aim of the labour unions was not to benefit the workers, but to carry out the state's economic policy under their cosy relationship with the ruling party.

This economic policy, which peaked in the 1950s and 60s with the so-called "Mexican Miracle", saw rising incomes and improved standards of living but the primary beneficiaries were the wealthy.^[44]

In the 1980s, Mexico began adhering to Washington Consensus policies, selling off state industries such as railroad and telecommunications to private industries.

The new owners had an antagonistic attitude towards unions, which, accustomed to comfortable relationships with the state, were not prepared to fight back.

A movement of new unions began to emerge under a more independent model, while the former institutionalized unions had become very corrupt, violent, and led by gangsters.

From the 1990s onwards, this new model of independent unions prevailed, a number of them represented by the National Union of Workers / Unión Nacional de Trabajadores.^[44]

Current old institutions like the Oil Workers Union and the National Education Workers' Union (Sindicato Nacional de Trabajadores de la Educación, or SNTE) are examples of how the use of government benefits are not being applied to improve the quality in the investigation of the use of oil or the basic education in Mexico as long as their leaders show publicly that they are living wealthily. With 1.4 million members, the teachers' union is Latin America's largest; half of Mexico's government employees are teachers. It controls school curriculums, and all teacher appointments. Until recently, retiring teachers routinely "gave" their lifelong appointment to a relative or "sell" it for anywhere in between $4,700 and $11,800.^[45]

Trade unions (Danish: Fagforeninger, Swedish: Fackföreningar) have a long tradition in Scandinavian society. Beginning in the mid-19th century, they today have a large impact on the nature of employment and workers' rights in many of the Nordic countries. One of the largest trade unions in Sweden is the Swedish Confederation of Trade Unions, (LO, Landsorganisationen), incorporating unions such as the Swedish Metal Workers' Union (IF Metall = Industrifacket Metall), the Swedish Electricians' Union (Svenska Elektrikerförbundet) and the Swedish Municipality Workers' Union (Svenska Kommunalarbetareförbundet, abbreviated Kommunal). One of the aims of IF Metall is to transform jobs into "good jobs", also called "developing jobs".^[46] Swedish system is strongly based on the so-called Swedish model, which argues the importance of collective agreements between trade unions and employers.^[17]

Today, the world's highest rates of union membership are in the Scandinavian countries. In 2010, the percentage of workers belonging to a union (labour union density) was 68.3% in Sweden and 54.8% in Norway, while it was 34.9% in Ireland and 18.4% in Germany.^[4] Excluding full-time students working part-time, Swedish union density was 67% in 2018.^[48] In all the Nordic countries with a Ghent system—Sweden,^[49] Denmark and Finland—union density is about 70%. The considerably raised membership fees of Swedish union unemployment funds implemented by the new center-right government in January 2007 caused large drops in membership in both unemployment funds and trade unions. From 2006 to 2008, union density declined by six percentage points: from 77% to 71%.^[50]

Moderate New Model Unions dominated the union movement from the mid-19th century and where trade unionism was stronger than the political labour movement until the formation and growth of the Labour Party in the early years of the 20th century.

Trade unionism in the United Kingdom was a major factor in some of the economic crises during the 1960s and the 1970s, culminating in the "Winter of Discontent" of late 1978 and early 1979, when a significant percentage of the nation's public sector workers went on strike. By this stage, some 12,000,000 workers in the United Kingdom were trade union members. However, the election of the Conservative Party led by Margaret Thatcher at the general election in May 1979, at the expense of Labour's James Callaghan, saw substantial trade union reform which saw the level of strikes fall. The level of trade union membership also fell sharply in the 1980s, and continued falling for most of the 1990s. The long decline of most of the industries in which manual trade unions were strong – e.g. steel, coal, printing, the docks – was one of the causes of this loss of trade union members.^[51]

In 2011 there were 6,135,126 members in TUC-affiliated unions, down from a peak of 12,172,508 in 1980.

Trade union density was 14.1% in the private sector and 56.5% in the public sector.^[52]

Labour unions are legally recognized as representatives of workers in many industries in the United States.

In the United States, trade unions were formed based on power with the people, not over the people like the government at the time.^[53] Their activity today centres on collective bargaining over wages, benefits and working conditions for their membership, and on representing their members in disputes with management over violations of contract provisions. Larger unions also typically engage in lobbying activities and supporting endorsed candidates at the state and federal level.

Most unions in America are aligned with one of two larger umbrella organizations: the AFL-CIO created in 1955, and the Change to Win Federation which split from the AFL-CIO in 2005. Both advocate policies and legislation on behalf of workers in the United States and Canada, and take an active role in politics. The AFL-CIO is especially concerned with global trade issues.

In 2010, the percentage of workers belonging to a union in the United States (or total labour union "density") was 11.4%, compared to 18.3% in Japan, 27.5% in Canada and 70% in Finland.^[4] Union membership in the private sector has fallen under 7%^[55] – levels not seen since 1932. Unions allege that employer-incited opposition has contributed to this decline in membership.

The most prominent unions are among public sector employees such as teachers, police and other non-managerial or non-executive federal, state, county and municipal employees. Members of unions are disproportionately older, male and residents of the Northeast, the Midwest, and California.^[56]

Union workers in the private sector average 10-30% higher pay than non-union in America after controlling for individual, job, and labour market characteristics.^[57] Because of their inherently governmental function, public sector workers are paid the same regardless of union affiliation or non-affiliation after controlling for individual, job, and labour market characteristics.

The economist Joseph Stiglitz has asserted that, "Strong unions have helped to reduce inequality, whereas weaker unions have made it easier for CEOs, sometimes working with market forces that they have helped shape, to increase it." The decline in unionization since the Second World War in the United States has been associated with a pronounced rise in income and wealth inequality and, since 1967, with loss of middle class income.^{[58][59][60][61]}

The Association of Vatican Lay Workers represents lay employees in the Vatican.

Unions may organize a particular section of skilled workers (craft unionism, traditionally found in Australia, Canada, Denmark, Norway, Sweden, Switzerland, the UK and the US^[3]), a cross-section of workers from various trades (general unionism, traditionally found in Australia, Belgium, Canada, Denmark, Netherlands, the UK and the US), or attempt to organize all workers within a particular industry (industrial unionism, found in Australia, Canada, Germany, Finland, Norway, South Korea, Sweden, Switzerland, the UK and the US). These unions are often divided into "locals", and united in national federations. These federations themselves will affiliate with Internationals, such as the International Trade Union Confederation. However, in Japan, union organization is slightly different due to the presence of enterprise unions, i.e. unions that are specific to a plant or company. These enterprise unions, however, join industry-wide federations which in turn are members of Rengo, the Japanese national trade union confederation.

In Western Europe, professional associations often carry out the functions of a trade union. In these cases, they may be negotiating for white-collar or professional workers, such as physicians, engineers or teachers. Typically such trade unions refrain from politics or pursue a more liberal politics than their blue-collar counterparts.

A union may acquire the status of a "juristic person" (an artificial legal entity), with a mandate to negotiate with employers for the workers it represents. In such cases, unions have certain legal rights, most importantly the right to engage in collective bargaining with the employer (or employers) over wages, working hours, and other terms and conditions of employment. The inability of the parties to reach an agreement may lead to industrial action, culminating in either strike action or management lockout, or binding arbitration. In extreme cases, violent or illegal activities may develop around these events.

In other circumstances, unions may not have the legal right to represent workers, or the right may be in question.

This lack of status can range from non-recognition of a union to political or criminal prosecution of union activists and members, with many cases of violence and deaths having been recorded historically.^[63]

Unions may also engage in broader political or social struggle.

Social Unionism encompasses many unions that use their organizational strength to advocate for social policies and legislation favourable to their members or to workers in general. As well, unions in some countries are closely aligned with political parties.

Unions are also delineated by the service model and the organizing model. The service model union focuses more on maintaining worker rights, providing services, and resolving disputes. Alternately, the organizing model typically involves full-time union organizers, who work by building up confidence, strong networks, and leaders within the workforce; and confrontational campaigns involving large numbers of union members. Many unions are a blend of these two philosophies, and the definitions of the models themselves are still debated.

In Britain, the perceived left-leaning nature of trade unions has resulted in the formation of a reactionary right-wing trade union called Solidarity which is supported by the far-right BNP. In Denmark, there are some newer apolitical "discount" unions who offer a very basic level of services, as opposed to the dominating Danish pattern of extensive services and organizing.^[64]

In contrast, in several European countries (e.g. Belgium, Denmark, the Netherlands and Switzerland), religious unions have existed for decades. These unions typically distanced themselves from some of the doctrines of orthodox Marxism, such as the preference of atheism and from rhetoric suggesting that employees' interests always are in conflict with those of employers. Some of these Christian unions have had some ties to centrist or conservative political movements and some do not regard strikes as acceptable political means for achieving employees' goals.^[3] In Poland, the biggest trade union Solidarity emerged as an anti-communist movement with religious nationalist overtones^[65] and today it supports the right-wing Law and Justice party.^[66]

Although their political structure and autonomy varies widely, union leaderships are usually formed through democratic elections.^[67] Some research, such as that conducted by the Australian Centre for Industrial Relations Research and Training,^[68] argues that unionized workers enjoy better conditions and wages than those who are not unionized.

Companies that employ workers with a union generally operate on one of several models:

An EU case concerning Italy stated that, "The principle of trade union freedom in the Italian system implies recognition of the right of the individual not to belong to any trade union ("negative" freedom of association/trade union freedom), and the unlawfulness of discrimination liable to cause harm to non-unionized employees."^[69]

In Britain, previous to this EU jurisprudence, a series of laws introduced during the 1980s by Margaret Thatcher's government restricted closed and union shops.

All agreements requiring a worker to join a union are now illegal.

In the United States, the Taft-Hartley Act of 1947 outlawed the closed shop.

In 2006, the European Court of Human Rights found Danish closed-shop agreements to be in breach of Article 11 of the European Convention on Human Rights and Fundamental Freedoms.

It was stressed that Denmark and Iceland were among a limited number of contracting states that continue to permit the conclusion of closed-shop agreements.^[70]

Union law varies from country to country, as does the function of unions.

For example, German and Dutch unions have played a greater role in management decisions through participation in corporate boards and co-determination than have unions in the United States.^[71] Moreover, in the United States, collective bargaining is most commonly undertaken by unions directly with employers, whereas in Austria, Denmark, Germany or Sweden, unions most often negotiate with employers associations.

Concerning labour market regulation in the EU, Gold (1993)^[72]*The%20Social%20Dimension%20%E2%80%93%20Employment]]*nd Hall (1994)

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. Thus, it comes closest to the above Anglo-Saxon model. Also, the Eastern European countries that have recently entered into the EU come closest to the Anglo-Saxon model.

In contrast, in Germany, the relation between individual employees and employers is considered to be asymmetrical.

In consequence, many working conditions are not negotiable due to a strong legal protection of individuals.

However, the German flavor or works legislation has as its main objective to create a balance of power between employees organized in unions and employers organized in employers associations.

This allows much wider legal boundaries for collective bargaining, compared to the narrow boundaries for individual negotiations.

As a condition to obtain the legal status of a trade union, employee associations need to prove that their leverage is strong enough to serve as a counterforce in negotiations with employers.

If such an employees association is competing against another union, its leverage may be questioned by unions and then evaluated in a court trial.

In Germany, only very few professional associations obtained the right to negotiate salaries and working conditions for their members, notably the medical doctors association Marburger Bund and the pilots association Vereinigung Cockpit.

The engineers association Verein Deutscher Ingenieure does not strive to act as a union, as it also represents the interests of engineering businesses.

Beyond the classification listed above, 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 the working class.

Typically this is a left-wing, socialist, or social democratic party, but many exceptions exist, including some of the aforementioned Christian unions.^[3] In the United States, trade unions are almost always aligned with the Democratic Party with a few exceptions. For example, 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. In Britain trade union movement's relationship with the Labour Party frayed as party leadership embarked on privatization plans at odds with what unions see as the worker's interests. However, it has strengthened once more after the Labour party's election of Ed Miliband, who beat his brother David Miliband to become leader of the party after Ed secured the trade union votes. Additionally, in the past, there was a group known as the Conservative Trade Unionists, or CTU, formed of people who sympathized with right wing Tory policy but were Trade Unionists.

Historically, the Republic of Korea has regulated collective bargaining by requiring employers to participate, but collective bargaining has only been legal if held in sessions before the lunar new year.

The largest trade union federation in the world is the Brussels-based International Trade Union Confederation (ITUC), which has approximately 309 affiliated organizations in 156 countries and territories, with a combined membership of 166 million. The ITUC is a federation of national trade union centres, such as the AFL-CIO in the United States and the Trades Union Congress in the United Kingdom. Other global trade union organizations include the World Federation of Trade Unions.

National and regional trade unions organizing in specific industry sectors or occupational groups also form global union federations, such as Union Network International, the International Transport Workers Federation, the International Federation of Journalists, the International Arts and Entertainment Alliance or Public Services International.

In the United States, the outsourcing of labour to Asia, Latin America, and Africa has been partially driven by increasing costs of union partnership, which gives other countries a comparative advantage in labour, making it more profitable to purchase disorganized, low-wage labour from these regions.^[75] Milton Friedman, economist and advocate of laissez-faire capitalism, sought to show that unionization produces higher wages (for the union members) at the expense of fewer jobs, and that, if some industries are unionized while others are not, wages will tend to decline in non-unionized industries.^[76]

On the other hand, several studies have emphasized so-called revitalization strategies where trade unions attempt to better represent labour market outsiders, such as the unemployed and precarious workers.

Thus, for instance, trade unions in both Nordic and southern European countries have devised collective bargaining agreements that improved the conditions of temporary agency workers.^[77]

Several studies have found evidence that trade unions can reduce competitiveness due to a reduction of business profit, which can then lead to job losses as it makes the business unable to compete.

Unions have also been criticized for prolonging recessions and depressions due to discouraging investment.^[78]

Several sources of current news exist about the trade union movement in the world.

These include LabourStart and the official website of the international trade union movement Global Unions. A source of international news about unions is RadioLabour which provides daily (Monday to Friday) news reports.

Labor Notes is the largest circulation cross-union publication remaining in the United States. It reports news and analysis about union activity or problems facing the labour movement. Another source of union news is the Workers Independent News, a news organization providing radio articles to independent and syndicated radio shows in the United States.