[VikingCoder]

Please don't be so rude, it doesn't add anything to the conversation.

There are many markets where you list a product for a price, and are legally bound to sell them at that price.

Those markets function, proving that withdrawing quotes is not necessary to make markets work.

[harryh]

What markets are those? I can think of no markets in which you're not allowed to change the price of whatever goods you're selling.

[VikingCoder]

Best Buy runs a flier with a price. You walk in, and Best Buy tells you they're not selling that product at that price... but they do have it in inventory at a higher price.

You drive up to a gas station, listing one price on its sign. By the time you pay, they've changed the price.

You see a house for sale. You make an offer, at that exact amount. There are no higher competing offers, but they want to back out.

You have legal recourse in each of those situations.

[harryh]

1) That's not because Best Buy isn't allowed to change prices. There's even fine print on their marketing that says the prices on the flyer are marketing only and may or may not match pricing when you get to the store. They just choose not to most of the time for marketing reasons.

2) Actually, at least in New York there are no regulations that discuss the large roadsign pricing signs at gas stations. The law just says the price on the pump must match what you get charged. If they change the price at the pump but get behind on updating their big sign you are SOL.

3) People back out of selling houses all the time.

And for all of these it's worth pointing out that what we're really arguing about is time scale. No one would argue that the gas station (for example) wasn't allowed to sell gas for a different price today than it charged yesterday right?

Bid and ask prices for securities just change prices faster than what we're used to for retail products.

To really expand the scope of this discussion it's worth noting that time scales for retail product price changes are actually shrinking. Walmart has experimented with electronic labels in stores that allow them to change prices in real time. Uber changes prices in real time based on demand. It's interesting to watch consumer reaction to these new trends.

[VikingCoder]

There's still bait-and-switch lawsuits... so advertising has some legal binding. I guess all advertisers know how to write in enough small print to get around it now, huh?

And I guess securities don't have any "this offer good for [x seconds]" on them. That's totally counter-intuitive to laymen, and speaking as a professional layman, I'm pretty sure I'm getting screwed because of it.

Electronic labels - you should be able to reserve a price for a time. Like, you want that shaving cream for $1.45, then you should be able to scan your Walmart member card at the electronic label to reserve that price. Should be valid for an hour, or a day, for up to X number of them.

...because the nightmare of picking it off the shelf, and the price is different when you check-out is just awful for consumers.

...and just to ramble a bit more... Sometimes it's cheaper for me to DRIVE to City A, fly back to my town, and then fly to my real destination than it is to book a flight from my town to my real destination. That's crazy, and I'm totally getting screwed, and I hope laws are enacted to stop that.

[harryh]

Ya, I get the whole "as a professional layman, I'm pretty sure I'm getting screwed because of it" when it comes to HFTs. But if you look at the actual data it's blindingly obvious that the exact opposite is happening. Trading costs have come down enormously!

Iit would be nice if folks looked at the data instead of falling back on their irrational gut logic.