Innovations which reduce the amount of human effort needed to do things also reduce the amount of human effort that is directly or indirectly needed per unit of goods or services consumed, and so to fund the same total consumption, less work per individual is needed.<p>There are three sides of the triangle which can move - the percentage unemployment, the number of hours per employee, or the total amount of consumption. Historically, people have simply consumed more - luxury is addictive, and people measure each other relative to what others in their community have.<p>However, there is a major counterbalancing force to efficiency gains - that there are only finite natural resources, and many easily accessible reserves are becoming depleted. Reserves of fossil fuels and high grade ores are declining fast, so increasingly more labour is required per unit of energy or metal - and the cumulative effects of pollution rise with accumulation over time and a rising population, more labour is required to prevent pollution.