In mainstream economic theories, the labour supply is the total hours (adjusted for intensity of effort) that workers wish to work at a given real wage rate. It is frequently represented graphically by a labour supply curve, which shows hypothetical wage rates plotted vertically and the amount of labour that an individual or group of individuals is willing to supply at that wage rate plotted horizontally. There are three distinct aspects to labor supply or expected hours of work: the fraction of the population who are employed, the average number of hours worked by those that are employed, and the average number of hours worked in the population as a whole.