Some Trade Unions Theories are:
Social-Psychological Approach of Robert Hoxie: Trade Unions grow out of the socio-psychological environment of the workers. Workers, who arc similarly situated economically and socially, closely associated and not very much divergent in temperament and training, tend to develop a common interpretation of their social situation and a common solution of their problems of living. This leads them to unite into a union. Thus differences of environment cause different unions to develop.
Sociological Approach of Frank Tannenbaun: Trade Unions are the by products of an industrial society in which customization has destroyed the old way of life and robbed the workers of his identity, purpose and creativity. Unions are a reflection of the worker’s spontaneous urge to reestablish his identity. Trade Unions help the worker in regaining his social life.
Protest Approach of Kerr, Dunlop and others: Trade Unions is form of organized protest against the evils of industrialization. Besides bringing about a basic change in the relationships between man and his work and between man and his cultural setting, industrialization inevitably circumscribes workers freedom by imposing discipline. The worker often finds his work distasteful and his compensation never commensurate with his contribution. Formation of a union is one of the organized forms of protest an expression of the workers resentment over the prevailing industrial system.
Industrial Democracy Approach of Webs: Trade Unions are the means to achieve industrial democracy They assert that political democracy alone cannot yield to the worker the fruits of freedom of contract, freedom of association, freedom of opportunity, etc. He can enjoy the fruits of political democracy only when he is granted industrial democracy, which means that he is given say in running the industry.
Classless society Approach of Karl Marx: Trade Unions represent a prime instrument for destroying the capitalist class. Although these unions by themselves cannot bring about a class-less society still they are important to carry on the economic struggle against the oppression and to bring about a revolutionary transformation of the working class.
Sarvodaya Approach of Gandhi: Trade Unions as essentially reformist organizations whose main function is to raise the moral and intellectual standards of labor. They are in the largest degree political. Their main aim is to increase their internal strength to work conscientiously and to take form the employer no more than what is rightfully due to the laborers.