A/HRC/9/23 page 28 structural in nature. Weather-related events in 2005-2006 led to worse-than-expected harvests in certain major cereal-exporting countries, although the overall level of production remained stable. But more importantly, agricultural production needs time to adapt to price signals, because it requires new investments, the absorption of new technologies or the switch to higher-priced crops. In the current context, the cost of energy, both for production of food and for freight, further slowed down the ability of producers to respond to demand. And in many regions, agricultural producers have been unable to continue improving their productivity per hectare as they have been doing since the 1960s - either because the productivity is already such that margins for improvement are almost non-existent (as in the EU and in the United States, Canada or Australia), or because of insufficient access to credit and infrastructures, depleted soils, and a system of international trade in agricultural products which has reduced agricultural production in those countries to lower-than-subsistence levels after the 1980s (as in Sub-Saharan Africa where important margins subsist for productivity improvements). 3. On the demand side, the continuation of levels of consumption in the industrialized countries, particularly of animal protein-rich food such as dairy products and meat, which would be unsustainable if they were to be replicated universally, and improving diets in large, fast-growing economies - although they still lag far behind the levels of consumption achieved in the OECD countries - have further contributed to putting pressure on the markets. These changes in diets multiply the impact of natural population growth, which increases by about 75 million persons each year. Finally, the resulting increase of the prices of agricultural primary commodities on the international markets was severely exacerbated by (although not caused by) the arrival on those markets of non-commercial investors, who massively shifted to primary agricultural commodities in 2006 and especially 2007. While there remains disagreement about whether this, per se, contributed to the soaring of prices, it certainly did lead to more volatility in the concerned markets. 2. The crisis in historical perspective 4. There is some analogy between the current crisis and earlier episodes. Following the oil price shocks of 1973 and 1979, sudden supply-side shocks already had sent commodity prices significantly higher. Especially in 1972-1973, due to wheat harvest failures in the USSR, the prices of grain went up in proportions comparable to those we are witnessing today. After the Soviet Union decided to buy significant quantities of grain on the world markets, prices trebled between mid-1972 and mid-1973. As a result of this peak in prices, the private sector invested more into agriculture, and national policies were set in place to encourage production. As a consequence of the resulting efficiency gains, prices were brought down to their previous levels.55 The tendency towards constantly lower prices continued throughout the 1980s and 55 Global commodities: a long term vision for stable, secure and sustainable global markets, HM Treasury, United Kingdom, June 2008, available from www.hm-treasury.gov.uk.