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Do Sin Taxes Actually Work?

March 18, 2025 / 13:22

This episode of The Ripple Effect features Ben Lockwood, Assistant Professor of Business, Economics and Public Policy at Wharton, discussing sin taxes, particularly on soda, and their impact on consumer behavior.

Lockwood shares findings from his research on Philadelphia's soda tax, which reduced soda purchases by nearly 50% within the city, with some consumers opting to purchase soda outside city limits, resulting in a 25% overall reduction.

The conversation covers the effectiveness of sin taxes in changing purchasing habits and the potential long-term health impacts of reduced soda consumption, though Lockwood notes that health benefits may take years to materialize.

Lockwood also addresses the growing trend of implementing sin taxes on various products, including online gaming and marijuana, and the implications of these taxes on different income groups.

He emphasizes the importance of understanding consumer behavior and the revenue implications for cities and states when considering the implementation of sin taxes.

TL;DR

Ben Lockwood discusses the impact of soda sin taxes on consumer behavior and public health in Philadelphia.

Episode

13:22
00:00:00
Ben Lockwood: My read of the current evidence
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is that that tax reduced total
00:00:05
soda purchases in the city of Philly by close to 50%, and then
00:00:11
around half of that reduction reappeared outside the city as
00:00:16
sort of cross-border purchases. So you go into Jersey, or you go
00:00:19
outside, you go up to the Main Line or wherever those taxes
00:00:22
aren't in effect, and you buy your soda there instead. So some
00:00:25
of it gets offset by that kind of cross-border shopping. But
00:00:28
still, that's something like a 25%
00:00:30
reduction in total purchases.
00:00:32
- Welcome to <i>The Ripple Effect</i>, the podcast that takes you on a
00:00:36
journey through the minds of Wharton faculty. I'm your host,
00:00:39
Dan Loney, and in each episode, we'll be diving deep into the
00:00:42
inspiration behind the groundbreaking research that
00:00:45
Wharton professors have conducted and exploring how
00:00:48
their findings resonate with the world today.
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Dan Loney: Have you ever heard
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of a sin tax? It's a type of tax put forward by a city or a state
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primarily to add a cost to something that may not be the
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healthiest or the best for us. There have been sin taxes on
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things like soda, tobacco products, alcohol and others,
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and they may even be growing in use to raise needed revenues.
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But do these sin taxes actually impact the public's thought
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process enough to change their behavior in using them? This is
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research conducted by Wharton's Ben Lockwood, who's an Assistant
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Professor of Business, Economics and Public Policy, and he joins
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me here in the studio.
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Great to see you, Ben. Thanks for your time.
00:01:32
Sure thing. Thanks for having me on, Dan.
00:01:34
So the research looks in kind of the mindset of the people as these
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sin taxes are implemented, and whether or not they actually
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have an impact on their purchasing habits?
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Yeah, that's the idea. So I've done a couple of research papers
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in this area, sort of ranging from the general theory and an
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understanding of how sin taxes work and how effective they
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might be, when you might want to use them. Obviously, they're
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pretty— they're used on a bunch of different products, from
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alcohol to cigarettes to— to other forms of tobacco, to now
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sometimes gambling or soda. And then more specifically, I've
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kind of zeroed in on a couple of particular types of sin taxes—
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one big set of projects on soda taxes, specifically, another set
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of projects on gambling in the form of state-run lotteries— to
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kind of understand what the trade offs were and what the
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behavioral effects were in those specific areas.
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And so with the sin tax— and we've talked about it in the past,
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with here in Philadelphia, with the sin tax that was put into
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place, what kind of research do we know or impact do we know
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from having that on soda, and whether or not it had an impact
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on sales here in Philadelphia? - Sure.
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So now— it's been several years ago now, maybe close to a decade
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ago, Philadelphia implemented a 1.5 cents per ounce tax on
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sweetened beverages. So soda, but also diet soda, and also
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some other kinds of, you know, non-carbonated sweetened drinks.
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And 1.5 cents per ounce might not sound like a very large
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amount, but actually, the average cost of soda in the US
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is something like 4 to 5 cents per ounce, so something
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like a 30% tax. It's actually pretty substantial. Now there's
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enough of a track record, enough evidence over these last several
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years, to kind of see what sort of effects that's had. My read
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of the current evidence is that that tax reduced total soda
00:03:29
purchases in the city of Philly by close to 50%. And then around
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half of that reduction reappeared outside the city as
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sort of cross-border purchases. So you go into Jersey, or you go
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outside, you go up to the Main Line or wherever those taxes
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aren't in effect, and you buy your soda there instead. So some
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of it gets offset by that kind of cross-border shopping. But
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still, that's something like a 25% reduction in total
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purchases. So it's not trivial, regardless. - But
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that's the interesting thing, is that people would even consider
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the fact of not buying their soda within the city limits, but
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they actually would go outside the borders. And I guess it's
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probably people who are probably close to the borders in general,
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go a mile, go two miles, whatever, to buy their soda and
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then bring it back into their—
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into their residence in the city limits.
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Yeah, I think that's right. So it's people who sort of live
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close to the edges. I think there's some evidence for— for
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sort of being geographically close to the edges, and also
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being people who kind of chain their trips together and do a
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large set of purchases, you know, at the Costco nearby or
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something, and then that's when you get all your— all your soda.
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In the research that we do, one implication of them is, if you
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do want to do this sort of sin taxation, it can be beneficial
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to try to implement those taxes at sort of a larger geographic
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area, because the smaller the area is that these taxes are
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confined in, the more you just lose any of their revenue-
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raising ability, and also any of their sort of desired behavioral
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effects, to people who are just cross-border shopping.
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So it's interesting you said that the amount of soda went down as
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much as it did. And again, that component of how much the tax is
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in comparison to how much a person might spend on a soda is
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very unique. And you wonder whether or not there's actual
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recognition by the public of the difference in cost because of
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that sin tax component itself. - Yeah,
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so you might wonder about this. And you know, often— this is not
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specific to sin taxes. Often in economics generally, people are
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sort of surprised to find out that small price changes can
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nevertheless generate kind of a change in total behavior. So you
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know, the price of a $30,000 car goes— or these days it's
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probably a $60,000 car, goes up by $1,000 and it's like, does
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anyone pay attention to that? But you can see in the data, you
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know, demand curves slope down, just like they— just like we
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teach in our MBA classes. And you can see in the data that
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there were some people who were a little bit on the margin
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between this and something else, or between buying now or— or
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waiting till next year, whatever. And you do see some—
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some effect in response to that. So this is sort of echoing
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those— those general results, that even small price changes do
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create changes in how much people purchase.
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Can you determine, then, maybe even larger-scale impact on health
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and maybe other components because of a lowering in the
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consumption, or at least the purchase, of soda
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within the city of Philadelphia?
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So, you might be able to see this sort of thing eventually. Now,
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from the— from the way that we think that, you know, health
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consequences of sugar consumption operate,
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you might not actually expect these things to materialize for, you
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know, 10 years down the road or something, with reductions in
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diabetes contraction. And even then, you know, many people who
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lived in Philadelphia at the time might now live in Florida
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or somewhere else. So I would be surprised if we're able to pick
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up very much direct effect for sort of the— this quasi-
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experiment of the soda tax being implemented here. But there is
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evidence, more generally, of, you know, the effects of sugar
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consumption on health down the road and other types of
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consumption. Certainly in the case of cigarettes, for example.
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There's a lot of evidence about the linkage between smoking and
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cancer. - But because
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of the connection that seemingly cities and states will have to
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these taxes, I guess it's probably not a surprise that— you
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kind of alluded to before— the types of products that they may
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put a sin tax on is growing in the last few years as well.
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Yeah, I think that's true, partly because there is this
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sort of growing realization that some products might have these
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health consequences or— or what have you. From an economics
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perspective, the way I think about this is not necessarily
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that you need to tax things just because they have harmful health
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consequences. I mean, there are lots of things that might be
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harmful for one's health, but people are aware of those harms,
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and they're interested in doing the thing. You know, we don't
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necessarily tax mountain biking or rock climbing just because
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they can be dangerous. The way I think about this is, if there is
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some aspect of a cost, a health cost, or whatever else, that
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people aren't thinking about or aren't taking into account,
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either because of behavioral biases or because they aren't
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aware of the information or whatever, then what you want to
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try to understand is, you know, if they were fully informed and
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if they really understood the context and the consequences and
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everything of all their actions, would they be consuming less
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than they currently are? And if so, that's a situation where you
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might want to impose a tax to try to get— sort of bring their
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actual consumption into line with what they might kind of
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rationally do if they took all those costs into account, in
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pretty much the same way that, you know, we have this rationale
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for imposing a gas tax so that people take into account the
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negative externalities, the pollution consequences or the
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congestion consequences of— of buying gas,
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and bring it into line with—
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But from a public policy perspective, this— these have
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become important revenue drivers for cities and states to be able
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to have them in the mix of their— of their need to try and bring
00:08:56
revenues to provide services in other areas as well.
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It's true. And in a way, this is sort of one of the ironies of
00:09:02
sin taxation generally, as I think they're sometimes looked
00:09:05
to as a potential source of revenues. But of course, if part
00:09:09
of the goal of the tax is to reduce people's consumption of
00:09:13
something that might be harmful for them, then if the tax works
00:09:16
well and people reduce their consumption a lot, then it
00:09:19
necessarily doesn't bring in as much in in revenue, right? So
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the way I think about the revenue question is that, you
00:09:25
know, whether you're talking about Philadelphia or the state
00:09:27
of Pennsylvania, or whatever jurisdiction, fundamentally, the
00:09:30
taxes that you bring in, that you need to bring in, are
00:09:33
determined by the jurisdictions' spending decisions and their—
00:09:36
their priorities. And then you're going to have to raise those—
00:09:38
you're going to have to cover that spending one way or another. If
00:09:41
you don't raise it via a soda tax, you're going to have to raise
00:09:43
the sales tax or the personal income tax or something else.
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And really, it's a question of which different things are we
00:09:49
going to tax, rather than, you know, should we tax soda at all?
00:09:52
What do you think, then, the
00:09:53
larger discussion is— and maybe it's—
00:09:54
it's a little bit of the health, a little bit of the taxation
00:09:57
side— of the impact that— that sin taxes are having in
00:10:02
communities around— around the country?
00:10:04
So I think there are a couple pieces to this. One is the kind
00:10:07
of behavioral consequence piece. Are people changing their
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behavior? Is that making them healthier or not? To what extent
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is it— is it having an effect there? Another piece of it is,
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you know, are there distributional consequences to
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this, which is sort of the fancy way that economists talk
00:10:22
about, you know, being— being really regressive or progressive
00:10:25
with your tax choices. Are you going to tax poorer people much
00:10:28
more heavily, or richer people more heavily? One thing that we
00:10:31
know about lots of these goods— soda, cigarettes, to some
00:10:35
extent, alcohol— is that they're more heavily consumed by people
00:10:38
who are sort of lower in the income distribution. And so a
00:10:41
thing you want to be aware of, a thing you want to be want to be
00:10:43
careful of, is, are you increasing taxes that are going
00:10:46
to sort of fall most heavily on people who are poorer? Now, there
00:10:50
are ways of offsetting that with like, you know, making the
00:10:52
income tax a little more progressive at the same time
00:10:55
that you impose some sin taxes that may, in a way— that sort of
00:10:58
offsets that distributional impact. But it is something that
00:11:01
you want to have in mind when
00:11:02
you're deciding on these kinds of tax policies.
00:11:03
So you're not really doubling up on the— on the component of
00:11:07
the tax. There's not a doubling of the impact on the people's
00:11:10
wallets because of the tax being included as well. - That's right.
00:11:13
- Yeah. What's your expectation, then, for looking at this
00:11:16
research and taking it forward?
00:11:18
It's a good question. So
00:11:20
there are a number of kind of increasing
00:11:23
future areas of potential sin taxation that I think are
00:11:26
becoming relevant. So some of these are— you know, there's
00:11:29
been an explosion in various forms of online gaming, sports
00:11:33
betting, this kind of stuff. There's also increasing
00:11:36
marijuana legalization, and that's viewed as a potential
00:11:38
sin tax base. And so with those sorts of areas too, my question
00:11:45
would be, to what extent are people buying those things or
00:11:48
doing those activities more than they would if they were sort of
00:11:51
fully rational or fully aware of the costs or— or fully cognizant
00:11:55
of this stuff? A flip side of that is that I think that, you
00:11:58
know, sort of for political reasons, there's sometimes a
00:12:01
drive to tax these new markets, just because they don't have an
00:12:04
entrenched body of stakeholders already that are existing and
00:12:07
that can oppose a tax. Now, from an economist point of view,
00:12:11
that's not really a good reason to tax them, just that nobody is
00:12:14
currently— currently consuming them a whole lot. Really, you
00:12:17
want to think about whether there are these, you know,
00:12:18
behavioral biases, and what the revenue trade offs are and that—
00:12:21
that that sort of thing. - But are
00:12:22
we at a point right now where you do see sin taxes in a
00:12:25
majority of states, or a lot of communities or cities within
00:12:30
states right now? - Yeah.
00:12:31
I mean, most states have, if you if you look at the set of
00:12:33
different sin taxes that are available from— lots of states
00:12:36
have alcohol excise taxes, cigarette taxes. Many states
00:12:40
have state-run lotteries, which I do think of as sort of a taxed
00:12:43
good, in the sense that the— you know, portion of the revenues
00:12:46
are withheld before the prizes are paid back out, and that goes
00:12:49
into the state's coffers. So between those things, you're at
00:12:52
a point where most states and an increasing number of localities,
00:12:55
of cities and smaller areas,
00:12:56
are imposing these kinds of taxes too.
00:12:59
Ben, great to have you here. Thanks very much for your time.
00:13:01
Thanks for having me on. - Thank you.
00:13:03
Ben Lockwood, Assistant Professor
00:13:04
of Business, Economics and Public Policy,
00:13:06
here at the Wharton School.
00:13:08
Thank you for listening to <i>The Ripple Effect</i>.
00:13:10
We hope you found this episode informative and engaging. Don't
00:13:13
forget to subscribe and leave us a review so that we can continue
00:13:17
to bring you the best insight from the Wharton School.

Episode Highlights

  • Impact of Soda Tax in Philadelphia
    Research shows a 25% reduction in total soda purchases due to the soda tax.
    “That's something like a 25% reduction in total purchases.”
    @ 00m 28s
    March 18, 2025
  • The Ripple Effect Podcast
    Join host Dan Loney as he explores the groundbreaking research of Wharton faculty.
    @ 00m 32s
    March 18, 2025
  • Behavioral Economics of Sin Taxes
    Ben Lockwood discusses how small price changes can significantly alter consumer behavior.
    “Even small price changes do create changes in how much people purchase.”
    @ 06m 08s
    March 18, 2025

Episode Quotes

  • That's something like a 25% reduction in total purchases.
    Do Sin Taxes Actually Work?
  • Even small price changes do create changes in how much people purchase.
    Do Sin Taxes Actually Work?

Key Moments

  • Soda Tax Impact00:28
  • Behavioral Economics06:08
  • Distributional Consequences10:41

Words per Minute Over Time

Vibes Breakdown

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