Suppose the following:
1. Gasoline prices fall by 50%
2. Gasoline consumption does not change.
3. Consumers do not use gas savings to purchase other goods and services.
Wouldn't total gdp fall?
Maybe I am confused by how GDP is calculated. But if I am correct, then maybe this is why it looks like the oil price savings aren't reflected in GDP measurements and won't be until oil prices have bottomed out.
If the US is a net importer of oil, then falling oil prices is obviously good for the US economy. If the US is a net exporter of oil, then falling oil prices is obviously bad for the US economy.
In terms of the world economy, it would depend on why oil prices are falling. If it is due to new abundance of oil, then it is good for the world economy. If it is due to a decrease in the demand for oil, then it again depends on why demand has decreased.
I believe that the lowering of gas prices helps out everybody and especially the U.S economy. We as people are able to spend more on luxury items, and also able to do more things. We are able to vacation, and spend more on items that boost the economy. We can shop more for things we want, and not just need. We are taking that extra money and pumping it back into the U.S. Economy.
There are definitely sectors of the US economy that will be hurt by falling oil prices, not the least of which are the US-based oil companies and its offshoots. However, consumers will benefit from lower prices for gas and other utilities (in theory) which should offer additional disposable income for other things. This, again in theory, should help other parts of the economy get stronger and perhaps even thrive.
Falling oil prices are taking financial pressure off of the American people and increasing profit margins for all industries that rely on fossil fuels. There are those who would argue that it is causing decreased revenue for big oil companies - these companies are only one part of the picture for the economy, and this decreases should encourage the oil companies to innovate their business.
I think that falling oil prices are a bad thing for the economy. I think after all this there are going to be a lot of people out of jobs and such but I must admitt that it is good on my wallet when it comes to filling up my car!