Bread, water, fuel: for a growing proportion of the world's population, particularly in Latin America, Asia and Africa, dizzying price increases are making these basic necessities increasingly unaffordable. With wars and climate change, the impossibility of access to the minimum subsistence level is now one of the main causes of migration on the planet and the aggravating factor of armed conflicts. These sharp increases in the cost of living often originate in new forms of speculation on raw materials, which create worldwide price movements totally disconnected from local markets, a devastating "butterfly effect".