1. The US has a high rate of vehicle ownership at 2.28 vehicles per household according to a recent survey. From the same survey, “'The most common pairing of vehicles in American households with two to four cars is a full-sized pickup truck and a standard, mid-range vehicle.” The average efficiency of the US vehicle fleet is in the low 20 mpg range.
3. In the developing world there is usually less than one vehicle per household and these vehicles are very efficient (such as a motorcycle/tiny car). Public mass transit is often much less available than in Europe and the US.
When oil prices rise rapidly, households in the US have capacity for immediate efficiency gains as they can drive the more efficient of their two vehicles more and if they buy a new vehicle they can buy a much more efficient vehicle. There is a certain amount of discretionary oil spending in the US (especially vacations involving air travel) which can also be cut back rapidly.
Europeans are already driving relatively efficient vehicles and so they have less capacity for immediate oil consumption efficiency apart from using public transportation more heavily. Europeans have less discretionary oil spending (as GDP per capita is lower) compared to the US - but what discretionary oil spending exists is still oil price sensitive.
In the developing world, there is less public transportation available and vehicle owners are already driving one very efficient vehicle. This vehicle is usually essential to getting to and from a good job and there is little oil spent on vacations (jet travel, and so on). Developing country oil consumers, therefore, have the least ability to cut back on consumption when oil prices rise.
In summary, when oil prices rise, households in the US can (to a certain extent) quickly decide to buy less oil, followed closely by Europe – but for slightly different reasons. In the developing world, households cannot as easily avoid buying oil when prices rise quickly.
This demand model was clearly evident in the rapid increase in oil prices during 2008 when US oil demand collapsed first and most severely (almost 13% year/year decline at its nadir in October 2008), followed by Europe. Developing world oil demand fell only very slightly, but quickly recovered.