**Joan Robinson**, in her book **The Accumulation of Capital**^{[1]} published in 1956, propagated a simple growth model, which reflects the working of a pure capitalist economy, also known as “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**,^{[2][3]} 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**:^{[4]}

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

The model

The entrepreneurs’ total profit and the workers’ total wage bill constitute the net national income. It can be mathematically expressed as

*pY=wN+πpK*

where *Y* is the net national income, *w* is the money wage rate, *N* is 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.

References

**^**Joan Robinson,*The Accumulation of Capital*(London: Macmillan & Co. Ltd., 1956)**^**Joan Robinson,*Essays in the Theory of Economic Growth*(London: Macmillan & Co. Ltd., 1963)**^***Hamberg, D. (1963). “Essays in the Theory of Economic Growth by Joan Robinson”. American Economic Review.***53**(5): 1109–1114.**^***Mishra, S. K.; Puri, V. K. Economics of Development and Planning. ISBN 978-81-8488-829-4.*