Joan Robinson's growth model

Joan Robinson in her book The Accumulation of Capital published in 1956, propagated a simple growth model, which reflects the working of a pure capitalist economy, also known as the "Joan Robinson's Growth Model". However, the Accumulation of Capital was a terse book and in one of her other books entitled Essays in the theory of Economic Growth, she tried to lower the degree of abstraction. The growth model was propagated in verbal terms, where later on the mathematical formalization was put forward by Kenneth K. Kurihara.

Assumptions:

1. There is a laissez-faire closed economy.
2. The factors of production are capital and labour only.
3. There is neutral technical progress.
4. There are only two classes: workers and entrepreneurs among whom the national income is distributed.
5. Workers save nothing and spend their wage income on consumption.
6. Entrepreneurs consume nothing, but save and invest their entire income for capital formation.
7. There is no change in the price level.
8. Saving is a function of profit.

The Model

The entrepreneurs total profit and the workers total wage bill constitute the Net National Income in Joan Robinson's Growth Model. It can be mathematically expressed as
pY=wN+πpK
where Y is the net national income, w is the money wage rate, N the number of workers employed, K is the amount of capital utilized, p is the average price of output as well as of capital and π is the gross profit rate (including the rate).

Further reading

Original sources

• Robinson, Joan (1956) The Accumulation of Capital London: Macmillan & Co. Ltd.
• Robinson, Joan (1963) Essays in the Theory of Economic Growth London: Macmillan & Co. Ltd. 1963)

Additional sources