Abstract: The similarity of the distributions of income in some Western countries in recent years that was demonstrated in the last chapter prompts conjecture that this kind of distribution is governed throughout by laws that take much the same effect in countries otherwise set apart by many differences. However, these countries do have this in common: they are at the same stage of economic development, so it could be that in earlier stages of development their distributions were less alike. This thesis is examined first by looking in detail at the course of income distribution over nearly 300 years within the UK; substantial changes are observed over the period 1688–1984, the salient one being a relative reduction of higher incomes. The brief examination is made next of trends in the USA, which show a different pattern and a trend towards greater inequality. Lastly, there is a brief examination of trends in income distribution in developing countries, which seem to follow Simon Kuznetz's thesis of 1955: that inequality generally increases in the early stages of economic development, and then decreases; the reasons for this are discussed.

Keywords: change, developing countries, economic development, income distribution, inequality, Simon Kuznetz, statistics, temporal variation, UK, USA, Western countries,