[bryanlarsen]

Identical prices are often a sign of intense competition. Every gas station on a corner has the same price because it's a highly competitive market not because of collusion. The prices of the much more lucrative chocolate bars inside the gas stations are less likely to be identical.

[tzs]

Gas stations on the same corner (or almost the same) in fact frequently have different prices, often quite different. A few examples.

https://maps.app.goo.gl/AeRZsAeGQAHoYvd36

https://maps.app.goo.gl/cdcbxQuEYLBFVECc7

https://maps.app.goo.gl/k8zAVMrwxkKYsoA8A

https://maps.app.goo.gl/nrQmyShTk9P8YEmo9

Too many consumers think that there are enough differences in additives and detergents between the brands for it to make a significant different in mpg and in maintenance costs, so buy from "their" brand even if there is a cheaper brand nearby.

At one time those consumers would have been right, but first the EPA established certain minimal standards that all brands had to meet. The better brands were still better for your car than the ones just meeting the minimum, but it would take longer for it to make a significant difference.

Then BMW, GM, Honda, and Toyota made a spec for what makes a good detergents and additive mix, and most other major automakers joined. They created a certification, "TOP TIER", that gas companies that met that standard could use.

Nowadays most gas in the US is certified TOP TIER. Generally you will only find non-TOP TIER gas at stations not part of a major chain, at some gas brands owned by grocery chains (Safeway for example), and at some gas brands owned by convenience stores (7-Eleven for example).

Most independent tests have found that and detergents and additives beyond those required for TOP TIER certification do not make a significant difference, even cumulative over 300+k miles.

Nowadays then in the US just buy from any TOP TIER brand and that will be good enough. But consumers don't seem to know that and so for a large number of consumers different brands on the same corner aren't actually in competition.

[bryanlarsen]

This is a good signal of how competitive your gas market is. Your examples are Seattle and the valley, which are very difficult markets for gas stations, so unsurprisingly are uncompetitive.

The whole US gas station market has gotten less competitive over the last 40 years I've been observing prices and big coastal cities are a lot worse than anywhere else.

[dcrazy]

Yes, the gas station example is directly cited in the article I linked to. It’s legal for a gas station owner, with knowledge and consideration of a competitor’s price, to reduce their price to the same or just below. What is illegal is for nominally-competing gas station owners in an area to conspire to keep their prices within a range of each other’s, even without explicit agreement.

[bryanlarsen]

The article you linked seems to indicate that there has to be active communication between the gas station owners for there to be collusion.

When I worked at a gas station as a teenager there was definitely an unspoken implicit agreement that the price of gas would be 6 cents/liter above wholesale IIRC. Which was highly competitive and didn't completely cover costs.

[lightedman]

"Every gas station on a corner has the same price because it's a highly competitive market not because of collusion."

Huh? I can go to most any gas station-occupied intersection and you will always find two that match and one (usually a Persian-owned Chevron) which is consistently a dollar or more higher per gallon across all grades of fuel.

[BeetleB]

Same here. I've never seen 2 gas stations near each other offer the same price. And large price disparities are common.