Those with high wages which compensate them for unpleasant aspects of their jobs

Those with high wages which result from them possessing the innate ability to develop some skill to a very high level

Those with low wages which can be paid because their jobs have other very pleasant aspects

Those with low wages which result from no need to have a period of training

The employer is called a monopsonist

The employer faces an upward sloping supply curve for labour, which is also the average cost of labour, ACL

The employer hires more labour so long as the MP of that labour exceeds the marginal cost of that labour, MCL

The wage paid equals the MP of the labour hired

In a competitive labour market, a minimum wage creates a kinked supply curve

In a competitive labour market where a minimum wage has already increased the wage, a rise in the minimum wage always reduces the quantity of labour that is demanded

In a monopsonistic labour market, a minimum wage creates a two-part MCL curve

In a monopsonistic labour market where a minimum wage has alreadt increased the wage, a rise in the minimum wage always reduces the quantity of labour that is demanded

They have many roles in addition to negotiating wages

If they negotiate a higher wage in a competitive labour market, they will result in employers wanting to hire less labour

If they negotiate a higher wage with a monopsonistic employer, they will always make the employer want less labour

They may attempt to alter the demand curve for labour

Efficiency wages are paid only to discourage shirking

Efficiency wages discourage shirking because they create an excess supply of labour, so a shirking worker who was dismissed might face a lengthy period of unemployment

The no shirking constraint curve shows the number of non-shirkers who could be hired at each wage

The efficiency wage is above the market wage