[silisili]

I'm...skeptical. Mostly that in a city where houses stretch into the millions now, people forego a can of Coke over a 20 cent price increase.

Soda consumption has been on a long decline since the late aughts. I even noticed as much anecdotally - often when dining out I would be the only one or maybe one of two to order a soda at all.

I'm completely willing to be proven wrong, but the data set is much too small to conclude anything either way. Why not include the top x cities, instead of just one 200 miles away? Because it rains a lot in both?

[gnicholas]

It's possible the decrease is driven largely by spending habits of low-income families:

> Last year, researchers at the University of Washington found that low-income families in particular saw a significant decrease in soda consumption following the implementation of the tax. The findings were based on a survey of residents, meaning that it relied on self-reporting, which is less accurate than sales data.

This leads to interesting policy questions. For example, some people might complain that the tax is regressive and hits poorer families harder. A rebuttal to this is that obesity is also regressive, and if you wish to fight obesity you need to change behaviors of the people whom it afflicts. One way around this knotty issue is to take the money from this tax and use it for public services that disproportionally benefit the populations from whom it is generated. (I have no idea what the tax revenues in Seattle are used for.)

[bertjk]

> One way around this knotty issue is to take the money from this tax and use it for public services that disproportionally benefit the populations from whom it is generated. (I have no idea what the tax revenues in Seattle are used for.)

And now you've created a bureaucracy that can only maintain its existence if sugary drinks continue to sell well.

[inglor_cz]

Or if the sin tax is gradually expanded to cover almost everything in the grocery store.

[idontwantthis]

> It's possible the decrease is driven largely by spending habits of low-income families:

Which I think, isn't really caused by their low-income, but by their greater preference for soda.

Demand changes at the margin, so a $.20 increase is a $.20 increase to everyone. It depends how much you value the soda in the first place.

[gnicholas]

The price elasticity of demand (i.e., the amount someone changes purchasing decisions based on price changes) depend in part on how much of your budget the item takes up. For wealthy people, soda is a rounding error on a rounding error. For lower income folks, soda could be a small but noticeable percentage of their budget. So 20¢ is not 20¢ to everyone.

For my part, I know that teenager-me would have absolutely noticed this price increase, but adult me would not.

[TheDong]

> Why not include the top x cities, instead of just one 200 miles away? Because it rains a lot in both?

You can find the source here: https://doi.org/10.1016/j.ehb.2020.100856

To quote from it:

> Portland, OR, was selected as the comparison site for Seattle, WA, based on Mahalanobis distance matching to evaluate the four largest municipalities in each of Washington and Oregon as potential comparison sites [etc]

They had more of a reason and included the model they used to pick the city.

It's also quite beneficial to keep the areas somewhat near in that there will be less variance in the number of item codes between close locations (i.e. different drinks are sold on the east coast vs west coast since some brands are local)

From a different section:

> Custom-ordered data were provided from store outlets geocoded within the boundaries of the taxing jurisdiction of Seattle, WA, the comparison site, Portland, OR

I suspect they didn't have enough funding to afford more geocoded scanner data given that it sounds like they had to pay for custom data at a rate per-geocoded location... or didn't have the funding to process that much more data.

It wasn't clear how much of the dataset labeling was manual, but it sounded like the study's authors may have had to sift through several thousand barcodes by hand.

[derbOac]

The comparison site seems suspicious to me. Why not use multiple comparisons? Why wasn't the study pre-registered (was it)?

[matheweis]

I’m skeptical too, but.. The data set is too small? It sounded enormous:

> The data set itself—gathered by marketing insight firm Nielsen—was huge, representing 45 percent of all food store sales in the city for 2017, 2018, and 2019.

One thing I’m curious about is whether they looked at adjacent cities. Seattle isn’t exactly an island, did the soda purchases just shift outside the city?

Did they look at restaurants and coffee shops or only grocery sales?

[cosmodisk]

When I arrived to the UK, a can of Coke was about £0.45. They kept increasing the prices each year and now it's probably about £1. It's not that I couldn't afford a can, but for me, paying a £1 for it became much less attractive and I only bough it a couple of times over the last two years.

[Lamad123]

The early seasons of The Sopranos almost always featured a lot of soda especially during family meals!! I don't see much of that in TV anymore.

[hugh-avherald]

> I'm...skeptical. Mostly that in a city where houses stretch into the millions now, people forego a can of Coke over a 20 cent price increase.

How can this possibly be your argument? Are you suggesting that prices have no effect on consumption when there are high prices in a completely different market? Your default hypothesis has to be that higher prices lead to lower consumption.

[seanmcdirmid]

People in Seattle with more money are already avoiding sugar for health reasons. The tax seems to be aimed at poorer consumers who would be influenced by it. Or it’s just a money grab by the SCC.