My preference would also be for “Youngian growth”, but without appending Kaldor’s name to it.

Kaldor was greatly influenced by Young, and his student notes on Young’s 1927-29 LSE lectures help elucidate Young’s 1928 presidential address to the British Association on “Increasing Returns and Economic Progress. However, Kaldor was too enamoured of Verdoorn’s “law” in which large-scale manufacturing was supposed to be the main source of productivity growth. Kaldor believed this called for special protection for manufacturing combined with taxation of services (hence the UK’s misguided “selective employment tax” in the 1960s); while agriculture was seen as an even more laggard sector.

Actually, the growth of agricultural productivity has been historically much faster than in manufacturing. It is a “drag” only because it has relatively very low elasticity of demand; and it was on real or "reciprocal" demand that Young fixed his attention. (Note too that Verdoorn later repudiated his own “law”.)

Lauchlin Currie, another of Young's students, insisted that neither Verdoorn nor Kaldor fully captured the essence of Young’s theory. This was that “increasing returns” were macro- rather than micro-economic – that is, associated with the _overall_ size of the market. Hence Young focused not on the size of individual firms (conventional “economies of scale”), nor on individual industries, nor even on individual sectors, but rather on the economics of specialisation, both within firms (Adam Smith’s focus) and, increasingly, by new firms, large and small, with "the representative firm" constantly losing its identity.

He argued that growth is a fundamentally endogenous cumulative process in which the division of labour depends upon the division of labour – “a useful tautology”. Currie extended this insight (in “Implications of an Endogenous Theory of Growth in Allyn Young’s Macroeconomic Concept of Increasing Returns”, HOPE 1997) by suggesting that the _rate_ of growth depends on the rate of growth, and so also tends to be self-sustaining rather than self-exhausting, absent policy shocks and apart from new technology that is genuinely exogenous (a relatively small part, he thought, pace Richard Lipsey). And, unlike with Kaldor or especially Schumpeter, growth would be faster if governments promoted competition and mobility rather than monopoly and protectionism.

- Roger Sandilands