was introduced in 1976 and by 1990 it was sown in more than 40 per cent of
rice-growing areas. The yield of the latest dwarf varieties of wheat in Sichuan
in the late 1970s was around 300kg per sown mu, far above the 70kg achieved
from traditional varieties, and rice hybrids yielded 500kg per sown mu
compared with 200kg from the traditional seeds (Bramall, 1993, 2009).
A paradox of appropriate technological change:
preventative interventions and a vaccine for malaria
Both economic theory and empirical evidence suggest we should have been
very pessimistic about the possibility of private-sector pharmaceutical compa-
nies engaging in medical R&D relevant to the needs of developing countries.
In the case of malarial vaccines those pessimistic views would have been
wrong. The vaccine market is now dynamic as never before and developing
countries appear to be among the principal beneficiaries.
Mortality declined worldwide after World War II because medical progress
in developed countries was transferred to developing countries (Cutler et al.,
2006:107). These were relatively low-technology public health interventions,
related to water supply, removing disease vectors (such as anopheles mosqui-
toes that carry malaria or rats that carry lice), the use of antibiotics, and wide-
spread immunization. Diffusion of this kind does not always offer such evident
benefits. Technology that may be well suited to a developed country with an
abundance of skilled labour (and relative shortage of unskilled labour), good
infrastructure (roads, power supply), low-cost capital (an efficient financial
system), and a temperate climate may be unsuited to the conditions of develop-
ing countries. Since around 95 per cent of patents are produced in developed
countries, there is a long-standing presumption among development econo-
mists that the thrust of technological change is likely to be biased towards the
conditions prevailing in developed countries.
Furthermore, the disease environment in developing countries differs
systematically from that in developed countries. This can be explained by a
mixture of differences in geography and in the prevalence of poverty.
Infectious and parasitic diseases account for one-third of the disease burden in
low-income countries (nearly half in Africa) and only 3 per cent of the burden
in high-income countries. Many diseases occur almost exclusively in develop-
ing countries. These include Chagas disease, dengue, ancylostomiasis and
necatoriasis (hookworm), Japanese encephalitis, lymphatic filariasis, malaria,
onchocerciasis (river blindness), schistomiasis, leprosy and pertussis (Kremer,
2002:71). The disease burden in developed countries consists mainly of non-
communicable conditions such as cancer and cardiovascular disease.
Not surprisingly medical research is biased towards more profitable devel-
oped-country diseases. Profits are largely determined by the size of a poten-
tial market, which in turn will be a product of the prevalence of a disease and
also the disposable income of those affected. In practice income has been the
Technology and Economic Growth 109