When, about thirty years ago, Richard K.Brown gave a speech to the British Sociological Association on research about working life, he said:

It never was satisfactory that ‘work’ should customarily be interpreted as referring solely to gainful employment in the official, formal economy. In the light of the sociological research and writing of the past decade or more such a restriction is completely untenable. In addition it deprives us of a major source of understanding and of explanation.[…] At the present time it is crucially important to maintain research and debate on the widest possible front.