Today we consider the causes of mass unemployment of the sort that most nations are enduring at present. This also involves the consideration of the relationship between wages and employment. This is an area in economics that has been hotly contested across paradigm lines for years. Mainstream economic commentators still claim that the employment situation can be improved if wages are cut. They are wrong. Modern monetary theory (MMT) is clear – mass unemployment arises when the budget deficit is too low. To reduce unemployment you have to increase aggregate demand. If private spending growth declines then net public spending has to fill the gap. In engaging this debate, we also have to be careful about using experience in one sector to make generalisations about the overall macroeconomic outcomes that might accompany a policy change.