Kremer (1993) argued that over the long sweep of history, ―larger initial populations have had faster technological change and population growth‖. Klasen and Nestman (2006: 14-15) argue that SubSaharan Africa‘s low population density hampered technological change, but that this may change now with rapid population growth. They add, though, that modern technology can be diffused even without high population densities, but that technological uptake is still slow in the region.

Simon (1981, 1996) built on Kuznets‘ thesis to argue that human innovation assures that population growth has long-term benefits for living standards, in both developing and developed countries. Contrary to the evidence from the wide range of studies summarized by Galor and Weil (2000), Simon (1996: 580) asserts that the ―standard of living has risen along with the size of the world‘s population since the beginning of recorded time...‖.

Simon argued that people and markets innovate in response to potential resource shortages, and therefore the resource base is effectively infinite. ―There is no physical or economic reason why human resourcefulness and enterprise cannot forever continue to respond to impending shortages and existing problems with new expedients that, after an adjustment period, leave us better off than before the problem arose‖ (Simon 1996:580). He argued further that human activity was not responsible for environmental damage, and that ―the trends toward greater cleanliness and less pollution of our air and water are even sharper than before‖ (Simon 1996:578).

For Simon, population growth helps resolve ― not cause ― resource scarcities and environmental problems. Simon and Boserup both argued that higher population densities can increase the economies of scale in providing productivity-enhancing infrastructure and services such as transport and extension services (Glover and Simon 1975; Boserup 1981).

Simon‘s arguments were supported by studies of the costs of some industrial resources. Potter and Christy (1962) for example, showed that mineral prices in the US actually fell by approximately 40 percent between 1870 and 1957, a period during which there was rapid growth in both population and industrial output. Barnett and Morse (1963) showed that the labor and capital inputs needed to produce scarce natural resources that included fuels, metals and non-metal minerals had more than halved over the same time-frame. For such clearly-priced resources, there are strong private incentives to find innovative ways of managing their use to keep prices down.

Certainly the Industrial Revolution and subsequent technological innovation enabled a huge jump in productive capacity, enabling rising levels of per capita GDP and consumption. The manufacturing sector also allows much more scope than the agrarian for absorbing a growing labor force. However, policy and institutional settings shape the scope for benefiting from the new technical possibilities. Much of the developing world lagged behind the developed world in putting policies in place to encourage economic growth, but this has changed in recent decades and their pace of growth has picked up.

The long view taken by some who argue that population growth can be accommodated by technological change discounts the deprivation faced by generations before the benefits of change manifest themselves ― even under the most conducive of circumstances. China is a good example, since its political system permits far more radical innovation that most others. From the end of the 1970s, a series of economic reforms were instituted − GDP per capita (in US$ Purchasing Power Parity terms) rose nearly 20-fold between 1980 and 2007 (IMF 2010a), and poverty levels fell sharply. This was helped by rapid fertility decline since 1970, when targets were set for implementation by local authorities.<sup>7</sup> Yet after decades of blistering economic growth and fertility decline, there are still significant levels of poverty in China. Almost a third of the rural population was consumption poor in at least one year between 2001 and 2004, using the dollar-a-day estimate in 1993 PPP dollars which is a low threshold by international standards (World Bank 2009: vi, 18). Using more average thresholds increases the estimated poor population substantially (Chen and Ravallion 2008).

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