The dominant economic theory, neoclassical economics, employs a single economic evaluative criterion: efficiency. Moreover, it assigns this criterion a very specific meaning. Other – heterodox – schools of thought in economics tend to use more open concepts of efficiency, related to common sense understandings of cost-saving and preventing waste. Also, to assess the state of an economy, heterodox schools of thought tend to draw upon additional evaluative criteria, such as stability, equity and sustainability. Economics’ widespread concern with efficiency is, of course, implied in the well-known definition of the subject as ‘the study of the allocation of scarce resources to alternative ends’. Here, the aspect regarded as mattering most is simply which allocation of resources helps to achieve the most ends.