Human Dimensions

Labor and capital are the classic factors of production but only the latter can be recognized and valued by property rights--the bedrock of business and national accounts--since humans aren't property. The result is 'separate but equal' accounting for 'labor'. This yields major differences in valuation for given streams of services and in which streams attach to which factor of production. Worse for accountants and modelers: the key residuals in mainstream accounts (multi-factor productivity, real holding gains/losses) remain analytically significant. This suggests a third factor of production. 

M-LA assumes this is what JR Hicks meant, at the end of Value and Capital, with "the system of economic relations we have been studying is nothing else but the form of a progressive economy" and ""we should do better to assume a good deal of variation in different people's elasticities of expectations". Something must interpret expectations enough to match production possibilities and consumer preferences; and willingness to invest to saving propensities. As in the World Bank's pioneering 1995 wealth metrics, M-LA call that Social Infrastructure and considers it a factor of production apart from labor, or Human Resources.