Labor economics Industrial relations 31 Working class 18 Labor supply 12 Labor unions 12 Wages 12 Labor 6 Labor policy 6 Economic policy 5 Trade-unions 5 Collective bargaining 4 History 4 Labor market 4 Research 4 Congresses 3 Economics 3 Government policy 3 Industrial policy 3 Manpower policy 3 Bibliography 2 Economic conditions 2 Industrial organization (Economic theory) 2 Inflation (Finance) 2 Labor movement 2 Social classes 2 Statistical methods 2 Unemployed 2 Aliens 1 Capitalism 1 Comparative industrial relations 1