The median voter theorem states that competing parties select their policies on any issue to meet the preferences of the median voter on that issue.

It is rational for voters to be ignorant

Bureaucrats may push for government spending at levels above the efficient level

Rent-seekers may push for government spending at levels below the efficient level.

The market demand curve represents the individual demand curves of all firms which hire this type of labour added together

The market demand curve may shift if there is a change in the behaviour of some firms which hire this type of labour.

The market demand curve may shift if there is change in the wage rate for this type of labour

The market demand curve may shift if there is a change in the number of firms which hire this type of labour.

Both X and Y.

X only

Y only.

Neither X nor Y

Its demand for labour is a derived demand

Its demand for labour depends on the marginal revenue product of the labour concerned

If the prices of other inputs that are used along with the labour increase, the firm would be sure to demand less labour

If labour became more productive, the firm would be sure to demand less labour

X has lower transfer earnings than Y

Because Y is earning some economic rent, the firm which hires Y could reduce the wage and Y would continue to work for that firm

If the wage for roofers generally fell enough to persuade Y to take up another occupation, X might continue to be a roofer

If we add up X’s economic rent and transfer earnings, we would get the same figure we would get if we add up Y’s economic rent and transfer earnings