- Welcome to MIT "Supply Chain Frontiers," presented by the MIT Center for Transportation & Logistics. I'm your host, Benjy Kantor. Each episode of "Supply Chain Frontiers" features center researchers and staff or experts from industry for in-depth conversations about supply chain management, logistics, education, and beyond. Today, we welcome David Correll, lecturer and research scientist at MIT CTL. He's led the annual State of Supply Chain Sustainability report for the past three years, and this episode, we'll dive into the findings of the most recent, the 2023 report. The State of Supply Chain Sustainability 2023 is a co-presentation of the MIT Center for Transportation & Logistics and the Council for Supply Chain Management Professionals, and was funded in part by generous support from Avetta, C.H. Robinson, and Isometric Technologies. The full report is available now for free at sscs.mit.edu. You may remember David from his past appearances of this podcast as both a guest and a host. Dave, you've left me some pretty big shoes to fill. Welcome back to "Supply Chain Frontiers."

- Thank you so much for having me, and I'm excited to get this conversation between you and me recorded.

- Yeah, so we'll dive right into it. First, really just to give everyone, laypeople and professionals both, give us a broad overview of what you mean by supply chain sustainability. When did people start paying attention to it?

- Sure, you know, and as I was thinking about what to bring to this conversation, I thought of what is probably the most disappointing but interesting way to answer that question, which is what motivates the study is that no one has the same notion of what the term means, you know? So when you very naturally ask the question, "Hey, what do we mean by this?" as a researcher, my inclination is to say, the fact that my answer is no good is the reason we do the study we do. So with that disappointment, I'll walk into it a little bit. One thing that I've observed is that we take the results of our research out into the world. You know, sometimes we encounter people who are already gung-ho about supply chain sustainability and wanna be part of their company's efforts to promote it. Other times, we run into people who are more skeptical of sustainability efforts in companies. The thing that I think brings everyone together is everyone is equally maddened by the fact that none of us mean the same thing by the term. So that's a long way of saying we're trying to narrow down the definition with the work we're doing. But I do think it's fair to say, well, in general, what do you mean? In general, we follow the UN Sustainable Development Guidelines, which include both environmental and social impacts of supply chain decisions across firm boundaries. So if I'm a company that's inputting materials, the impact on the environment and communities that surround my firm and my suppliers are part of a supply chain sustainability journey.

- I'm glad you mentioned that, 'cause actually, and this may be to confuse things, so I'm happy to confuse things a little bit, I think that public perception of sustainability is one of environmental concerns, like when a company says they're green, right, and applying that to their supply chains. But in terms of supply chain sustainability, there's also that relation to lowercase flexibility and strength but capital R, Resilience in terms of supply chain. The people who were taking the survey that led to this report, does their perception matter? What is their perception versus what definition you're using?

- Yeah, thank you, so their perception definitely matters. And the way I would think about it is it allows us to sort of not have to prescribe an answer. So when we started this project, there was actually some internal debate on the research team; does supply chain sustainability include social issues, like issues of social justice? Some people said, "No, no way. That's not part of sustainability. Don't ask about it." Other people on the research team said, "No, you know, in my heart, that is part of sustainability, ask about it." There was no good way to stop that fight except to say, we'll ask the world, and if the world says social issues are not part of it, then we'll stop asking. But the exact opposite turned out to be true. Sort of our first headline-making conclusion when we were able to first compare data was that social issues are, in fact, the fastest growing components of supply chain sustainability. So what the respondents say definitely matters, and that's what we're after. We're not trying to be prescriptive or didactic about how to do supply chain sustainability. We're really trying to just understand what is the state of play across geographies and industries as far as what's included in supply chain sustainability and how firms try to achieve it.

- And so what might be some of the social aspects of sustainability that folks are or are not familiar with?

- Excellent, yeah, so our survey asks about 10 different dimensions of supply chain sustainability, five environmental, five social. And the social ones are things like supplier diversity, equity, inclusion, fair pay and fair trade, employee health and safety, things that are outside of just the environmental components of our firm's operations. And one of the things that we've seen is that when we look at how firms act on environmental versus social issues, sometimes hesitancy to act is because it's, I think, hard for firms to know which actions to take to try to make a more socially sustainable supply chain. So in addition to the survey data that we collect, we also do executive interviews. And one of those that really struck with me was a gentleman who operates warehouse software. He designs warehouse software. And he said, "Look, Dave, I get it. You know, social issues are increasingly important around the world. We wanna be part of that. But if you tell me to make a greener warehouse, I know what to do. I know how to reduce energy costs. If you tell me how to make a more socially sustainable warehouse, I simply don't know how to take action." And so one of the things that we've uncovered, I think, through this report, is that there are myriad social issues. People feel pressure to act on them, but firms don't always know what their first step towards action is.

- Yeah, and the bulk of the... In fact, likely 100% of the people who are taking your survey that led this report are people from within these industries. But where is the pressure on companies coming from? Is it coming from internally, from their staff, from their employees, from their management? Or is it coming from a separate public piece, who wasn't necessarily providing data for you for this survey but is part of this general world of public perception and sustainability and greening and things like that?

- So that really gets to another one of, I think, our most surprising results is, you know, where does the pressure come from for firms to engage in supply chain sustainability in the first place? And two things really jump out to the research team as we've analyzed the data. And I should say that, you know, we're in our fourth year of data collection now. Each year we get around 2 to 3,000 respondents. So, you know, for the most recent year, we've got 2,300 respondents. But across the four years, that sums up to around 9,000 responses answering surveys that are translated into English, Spanish, simplified Chinese, and Portuguese. So we've got a pretty big picture. And I bring that up to say that over the four years, none of the 10 sources of pressure that we measure showed declines. So at least over the last four years, the pressure appears to really be real and ratcheting up. And when we look at which sources of pressure amongst the 10 that we measure are ratcheting up the most, far and away, the answer to the fastest-growing pressure is investors, a 25% increase over the four years compared to much smaller increases from other sectors. Investors is followed by corporate buyers, or B2B buyers. And that was really supported by the executive interview work we did, too, where firms suggested that the sources of capital, their lenders are the people who are really pushing them to invest in supply chain sustainability efforts.

- So from those investors in B2B, which of the areas of sustainability is driving their pressure, or what are the aspects of the supply chain and logistics that they're focusing on for that purpose?

- That's a great question, and our data only gets us so far before we have to infer, but we know that from our executive interviews, you know, we ask like, okay, well, how does that pressure show up? What does that really look like when your banker says be more sustainable? We know that it shows up in the form of questionnaires to firms: what are you doing about x, y, and z? And oftentimes, those relate to emissions. And so we did a whole deep dive on emissions in this year's report that maybe we'll get to talk about, and, you know, what is the motivation for that? This is where, you know, anyone who wants to to read our report is very welcome to. We're happy to be able to share it with the world for free. But one interpretation of why investors might be motivated to push for more sustainable supply chains, and why they're pushing in particular around emissions, is investors want the firms that they invest in to be ready for the legislation that's coming down the road. And there's some expectation around carbon prices, new restrictions on carbon emissions that investors want their firms to be ready for. You know, another potential motivation for investors is that sometimes the investors are investing in the brands, and a major environmental catastrophe or a major social catastrophe, for example, discovering child labor in the supply chain, can be really diminishing to the value of the brands that the investors are investing in. So those are some of the main motivations we hear, at least from our anecdotal research.

- And after four years of this report coming through CTL, this is perhaps asking for more inference on your part, but are the companies paying attention to the report? How much do they care, I guess, is the question, that they're receiving this pressure and that the investors are thinking about these kinds of things?

- That's a really fair question. So, you know, I do have to infer, as you say, so we don't have that barometer in our survey instrument, although I wish we did, but the-

- The, "Do you care? Yes or no," check mark is on next year's survey, right?

- Well, there's a few ways for us to at least give some insight into that important question. And one is that, you know, projects like this don't typically last for four years. So that we have continually found support for this project, you know, we're completely underwritten by sponsors, some of them repeat sponsors, you know, suggests to me that that's a real interest in learning about supply chain sustainability and positioning themselves as thought leaders in that space. Another question that we ask that I think is maybe helpful to at least getting insight to that question is, for each of the 10 dimensions, we ask respondents to rate their firm's investments in those issues and goals in those issues. And then we plot the difference between investments and goals at an aggregate level over the four years. So the first thing that we see is everyone sees that, everyone basically responds that their firm has a lot higher goals than their investments. So they don't put as much money down as they talk, colloquially speaking. What's interesting though is that the gap is closing. Over those four years, we still see that on the whole, goals exceed investments, but the gap has closed over the four years. And, in fact, it's closed most rapidly among social issues. So those are two things we can grab from the data that lead me to believe that, you know, I don't have a percentage estimate, you know, how much do people care, or what percentage of people really care, but those two things lead me to believe that firms care more than a cynic might expect.

- So we're seeing the lip service potentially decreasing-

- Yeah.

- and some act or action meeting up with the amount of talk.

- An action meeting up with the talk is part of it, you know, but another part of it is thinking about the story about the warehouse software engineer and, you know, his challenge to me, "Hey, Dave, look, I get it, I care, but I just don't know how to make a warehouse more socially sustainable." You know, I think over the four years that we've been in this space, that gap has been addressed entrepreneurially by people who are now making software solutions and supplier vetter solutions and bringing things to the marketplace to try to make firms more socially sustainable that didn't exist before. So I think maybe less lip service, but also that gap is being filled by people who wanna help firms on that journey.

- Yeah, it's funny, it reminds me of this story that we were hearing from your colleague Josué Velázquez, which, about the efforts that some companies are doing to actually make things greener or more sustainable in terms of supply chain that actually have a deleterious effect. So, like, the ways that they're packing things into freight actually ends up being more efficient and sustainable for packing things, but makes delivery and fuel consumption heavier. And so they have these sort of, like, interesting offsets for the efforts that they're trying to do. So it's that that conundrum of like, how do we make the warehouse-

- Oh yeah.

- sustainable. Yeah, interesting.

- And the upside of that from an educator's perspective is that, like, the most motivated students are always drawn to the hardest problems. And so when we see that, like, it's just not easy to even know what to do if a firm wants to make the most sustainable choice, because there are so many trade-offs, quantitative and qualitative, to balance in one's head. The downside is that it's hard. The upshot is that, you know, as someone who works with supply chain students all the time, hard problems draw great talent. And I think we're seeing that in our students, who really want to engage us on state-of-the-art sustainability projects.

- Yeah, and what's the... Like, does your team and your colleagues work on the most effective ways to approach it? Like, is it breaking these huge projects into doable tasks? Or for, you know, your warehouse manager example, like, how is it that they are eventually able to take steps in the direction they wanna go?

- Oh, I think like all science, the progress is incremental and maddeningly slow. So I think, you know, that we all cut out different parts of it that maybe we have the best potential to contribute to meaningfully. So, you know, you talked with Josué, and he's done all sorts of really cool vehicle routing problems, where, thinking about how to route the vehicles. Another one that's of interest to me is a challenge that needs to be solved in this particular case is like, so let's say I am a shipper, and I am committed to paying more for greener transportation, if someone can prove to me how much greener it is, and I can measure that against the extra cost of paying them to do it. And, frankly, those shippers exist. Those brokers exist. They come to our office and ask for help because it's not out there. Like, even how to quantify the benefit is not yet figured out. And why is it hard? And hard, it's part because, if you think about freight movements, they're oftentimes shared between different companies. How are we going to apportion the offset of carbon emissions that came from one truck moving multiple companies' freight? It's a lot to figure out. So hopefully researchers, like those of us at MIT CTL working on it, will move the ball a little bit before we retire.

- So certainly, in the grand scheme of things, sustainability within supply chain is still in its infancy. And supply chain as a study in and of itself is still sort of, in the grand scheme of things, in its infancy. And, also, I think one other potential roadblock or challenge is that conventional wisdom might say that sustainability would take a backseat during a major crisis, like the last few years, during COVID-19, right? But in your research, you've found that sustainability has proved resilient in the face of this. So why do you think that is? Have you seen any exceptions to that rule, or would you even call it a rule?

- Yeah, oh, thank you for finding that one, because I think that is our most surprising discovery, and maybe what we bring to the world that I hadn't seen previously documented. So what we did is decided that for better or for worse, over the last four years, there's been no shortage of crises, so we'll directly ask the question, how has this crisis impacted your firm's commitment to supply chain sustainability? We did two years of COVID. First year, we got roughly 80% of people, if they said, "Yes, this impacted my firm's commitment to supply chain sustainability," said, "Well, it actually increased it," versus 20% saying decreased. First time we saw that, personally, I thought, you know, something's wrong. Did we code the question wrong? I kind of thought in that environment, people would say, "Get off my back. I don't have time for this right now." We checked everything was right. We asked the question again another year. And we got the same result, which is, just from a research perspective, exciting. Because you rarely get the opportunity for replication in social sciences, but we had it here. And so we started asking in our executive interviews, what's this about? Why are firms that said COVID-19 changed their firm's supply chain sustainability effort saying that it increased it? And we heard back from multiple sources that, like, "COVID broke my supply chain. My management gave me new time and budget to fix it. And when I did it, I did it now with sustainability top of mind in a way that it wasn't way back when, when these supply lines were originally drawn." So, you know, for better or for worse, there's some benefit to the crisis, or at least some opportunity that came outta that crisis. And I bring those up because in this most recent year, we asked about two different crises. One was Russia's invasion of Ukraine, and the other was projections of economic recession in 2023. Focusing in on the Ukraine one first, you know, less people said it impacted their firm's commitment to supply chain sustainability, and most of those were in Europe. But when they said yes, we saw the same general phenomenon. The majority of the yes answers, the majority of respondents who said, "Yes, this crisis impacted my firm's commitment to supply chain sustainability," said that it increased it. When we started asking around and reading more and trying to understand what was going on, to my mind, the phenomenon was the same. Essentially, supply lines coming out of Russia were broken either by firms that were trying to de-Russify their supply chain or were just trying to avoid sanctions. That gave them, the supply chain managers for those companies, opportunities to redraw those lines. And when they redrew them, they did things to advance sustainability that they didn't have managerial permission to do before. And some of it was frankly motivated by a fear over lack of access to Russian hydrocarbons in the winter. It was much easier to say, "I'm gonna put electric vehicles in our fleet," in the face of that crisis than it was without that crisis. So in that sense, we see a surprising but consistently observed result that when supply lines are broken, sustainability seems to thrive. And that's something I would bet on from the research. Now, the flip side of that is that when we asked, "Did your firm's commitment to supply chain sustainability change as a result of projections of economic recession?" if they said yes, the phenomenon reverses. If they said yes, the majority said, "Well, we actually decreased our commitment." So to my mind, the inference is when supply lines are broken by crisis, sustainability thrives. But when downstream supply chains are starved of sales opportunities, that's when sustainability withers. Maybe another interpretation is that the commitment to supply chain sustainability is uniquely sensitive to projections of consumer demand, and it is not as sensitive to projections of supplier disruption. So it's almost like we're finding the funny bone, if you will, of supply chain sustainability. If you mess with or even give the impression that there's weakness in consumer demand, which is what I think the bottom line of a recession protection is, that's when the sustainability knob turns down. And so that's a uniquely sensitive pain point compared to if you say, you know, I think we're gonna have some real upstream upheaval, we're gonna lose some suppliers, that doesn't seem to have as sensitive of a connection to sustainability commitment.

- Well, and that was the question that was kind of coming up in my mind, which is the concept of sustainability as a way to address risk, as a way to improve resilience during a crisis or during conflict. Sounds like there's some buy-in there from the upper levels. When the world gets beyond conflict, when we've solved all the rest of the problems, will the C-suite respond in the same way towards committing resources to having sustainability be part of their risk management and resilience program? That's just a theoretical question at this point, I guess.

- Yeah, no, no, it's a fair question because I think another part of the reason that we observed the phenomenon that we did, and one respondent said it so well, he used military terminology, he said, "The pandemic gave me air cover to do the things I already wanted to do." So it gave people who were interested in improving their sustainability profile opportunity to do it, so that's part of the explanation. But I think the other part is like, the response or the counteraction to a supply chain crisis and a sustainability initiative have a lot of the same moves. It's invest in visibility, understand who your suppliers are, understand how they're producing, dig into that at a deeper level. So part of it is, I think, that it's essentially the same response to crisis or response to motivation, whether it's shoring up after a crisis or improving supply chain sustainability. Either way, you're digging deeper into your supplier's practices.

- So I guess shifting gears a little bit with relation to the past surveys and reports that have been done, we've been finding previous reports have found that sustainability efforts may vary widely by geographic reason. And at this point, I'll give a a thank you to our producer, Dan McCool, who is digging deep into the reports and finding some of these comparisons from year to year, in this particular example, where we find that the sustainability efforts are stronger in more economically prosperous global north areas. What's the story there? Do those areas that are having more success with more efforts and resources addressing it, do they have a responsibility to other areas, to global south countries, to help them become more sustainable within their logistics and supply chains?

- Oh yeah, that's one of the interesting but perhaps concerning results that's come up two years in a row now. So the first time we looked at geography, you know, we're comparing responses from all over the world, and that becomes sort of a lot of comparisons. You know, if I'm gonna say Europe versus Latin America, America versus the Middle East, Middle East versus Europe, it becomes a lot of comparisons to present. And so we thought, okay, what is a simple way to divide the world that might give us meaningful insight into how people around the world approach supply chain sustainability? We tried two, the first one, east versus west. So is it like a Cold War division? Second one, global north versus global south, is it an economic development division? the one that rang true statistically was global north versus global south. That's where we saw the most differences in how respondents prioritize different issues related to supply chain sustainability. We built on that this year with a deep dive on net zero goals. And we looked at where around the world are firms adopting net zero goals. And it really was a surprising result, or not surprising but kind of jarring result, when we saw that adoption in the US and in the European Union area, right around 50%, closer to 60 in the European Union. Adoption, in other parts of the world where we have a statistically significant sample, in Asia and Latin America, in the Caribbean, in the teens and the 20%. So the adoption of net zero goals really seems to be in this global north. And one of the charts in the report that gives me pause and usually gives audiences pause as I present this is if we use adoption on the y-axis and World Bank per capita GDP on the x-axis, a couple things jump out, and I encourage listeners, if you're interested in this, to go take a look at the chart. If we look at per capita GDP in the United States and in the European Union and compare it to the world per capita average, we're just way off. Like, our lived experience is so much different than the global experience. And if we look at where, the parts of the world where we have good responses, Latin America, the Caribbean, and parts of Asia, they're really in line with global per capita GDP, and there's far lower rates of net zero adoption there. So, you know, what does all that mean? One thing, it gives me pause in that net zero is intended to be a tool to fight a global problem, but it's a tool that's only being deployed in limited areas. So I think we might not have the right tool if we're trying to solve a global problem.

- This is the fourth annual report through CTL. At this point, what are the newest things that you're finding? Are there things that are coming to you at this point after four years that are surprising you? What are the biggest learnings that are being corroborated every year? You've touched on that a little bit, but it kind of goes into this questioning of, like, what happens beyond the fourth year? Are there things you still need to dig into or that you can find out, with a fifth survey perhaps, if that's something that you end up doing?

- Yeah, excellent, so yeah, the first things that jump out to me are the things that have been corroborated, which gives us, I think, confidence that we've documented a new and important phenomenon in the world, and that is the way that supply chain sustainability responds to what we call acute supplier disruptions. So we've seen that multiple times, and we'll continue testing, but that seems to be something new that it's understood around the world in different ways. That seems to be something important and that's corroborated, that I hope, you know, we can bring to the world's understanding of supply chain sustainability. What we don't have but what we need is that when we look at practices, we see that most firms have some sort of code of conduct. And for people who aren't familiar, what that really means, it just says, "These are our rules. Follow them." Far fewer firms have something where they say, "These are our rules," you know, speaking to their suppliers, "Let us help you develop up to them, if those aren't your rules." Far fewer have something even rarer to say, "Here are our sustainability goals. What are your sustainability goals? Let's figure out a mechanism to work on them together and share the benefits." But I think that's really is what needed. So I hope we get to go forward, and if we do, I think presenting readers go-bys or examples of how to work more deeply with your supply chain to achieve your sustainability goals is where we have to get to next.

- Just from some sort of, like, survey nitty-gritty, can you talk about the process of translating the survey into those multiple languages and kind of what went into that and how that helped with the distribution of the survey and getting to the final report?

- Oh, my pleasure, those are some of my favorite stories of our team's efforts on the project. So, you know, this year we went out in four languages, English, Spanish, Portuguese, and simplified Chinese. The way we do that is we do multiple passes through the translations with native speakers to make sure that we're getting at the right thing. So, you know, I'll work with the team to write the survey in English. We'll give it to some bilingual folks who speak each of the languages. They'll take a pass at translation. Then I'll convene another group of people who also are native speakers to make sure that that works out. And I bring up those mechanics because, you know, some of the most fascinating discussions for me, you know, where I've had great opportunity to learn as part of doing this research is convening the native speakers to talk about how they choose the words. And one that really jumps to mind is diversity. So we had, I believe, in year three, we had someone from Mexico, Columbia, and Peru reviewing our existing Spanish translation. So we had this group thinking about how we would ask questions about supplier diversity. And so one of the respondents said, "Oh, you know, these are programs that help hire people with physical handicaps." And then someone else said, "No, no, no, no, no. In my country, that means helping to support businesses that come from underrepresented communities." And then they described the underrepresented communities in their country. And we got into this battle about what does this mean. To my mind, that really kind of highlights what makes this study important but also difficult is that even in the notion of the words, there's so much packed into each respondent's head about how they're answering the questions, that we're all seeing things a little differently. And hopefully, with a report like this, we can at least present some global baselines that allow people to have a more productive conversation to get to, you know, here's where I'm at, and here's where you're at.

- And then once you sort of deciphered those or peeled them apart or put them back together again, I guess, what is it like when... What is it like on the ground for individuals working at companies or for companies themselves, when they're making these, when they're heading toward net zero, or when they're making improvements or addressing supply chain within sustainability? What are the specific kind of things that companies are now doing?

- Sure, so this is one of the resources that we're really proud of in the report. And I wanna highlight and thank everyone who contributed to this report, including Kellen Betts, who's also a researcher here on our team, who made some of these results filterable by geography and industry. And I bring that up and that, so one of the things we ask is, what is your firm doing about supply chain sustainability? And then we've built what we call the staircase of practices. So the bottom rung is what everyone's doing. And so that's like 80% of people have built their firm's sustainability code of conduct. These are our rules. And then you can climb up that staircase to sort of the rarer and rarer air of the lesser applied tools. And that's really a testament to Kellen's ingenuity that readers have really enjoyed. You can go in there and put, "Well, I work in manufacturing in Europe," and can see where you are relative to your peers on that benchmark. So anyone can see, you know, what firms are doing in their sector, as long as we have the data, by using those filterable tools at sscs.mit.edu. But the bottom line for everyone is that everyone seems to have documented something that they can point to that says, "These are our sustainability expectations." Those are communicated to their supplier base. I think that's sort of table stakes. The more aspirational stuff is helping suppliers develop to meet those and working with suppliers to share the benefits of sustainability wins across firm boundaries.

- And it looks like achieving those kind of goals or working towards those goals certainly would require a lot of collaboration between tiers of the supply chain, you know, the second, third, fourth, fifth tier of folks. So, and where the second and the fifth part of the chain are disassociated from each other, but they're so to tightly, you know, coordinated with each other, and it might not be there yet for a lot of industries, how do you see that evolving?

- That's a great point in that I think people outside of this world really over assume how available data is, you know, so I think, you know, if you're not working in this world, you would think that, you know, major companies, the Procters & Gambles of the world, the major motor companies of the world would have great visibility into everything that their many suppliers are doing and the ability to track the sustainability implications as far back as they want. But that is really far from the truth. And I don't speak to those companies specifically just to say that, you know, even firms that we think of as being quite powerful and quite established have trouble seeing that deep into their supply chain and having high-quality data about, you know, what are the emissions that deep in their supply chain? So, you know, one of the things, and some of the companies that worked with us on this year's report are trying to fill that gap by becoming just specialists in the recording and reporting of things like emissions data or employee health and safety data that can be tracked all the way back and up supply chains. But that's a current entrepreneurial innovation, not something that's existed for a while.

- Yeah, and this kind of goes back to what we were saying before of, like, this is, they have broken this into the doable piece, right? And from there, so yeah, that was my next question, which is, where do they start? It sounds like that's one example of like where you could start, because they are able to go back far enough where they can make tweaks or changes and make a difference. Whereas, when you start getting into your partners and your partner's partners and your partner's partner's partners is where a lot of these, it strikes me that a lot of these challenges are gonna last.

- Oh yeah, and the more painful part of that, too, or what adds difficulty is that, I think you're right, that if, you know, say a firm reads our report or reads something else and says, "Okay, I wanna do more here," certainly, you know, and like you said, the first step is get your own house in order. You know, makes sense, and particularly around things like energy conservation and in some ways what we'd call Scope 1 emissions, it's clear which steps to take and how to get there. But the real challenge is that most of a firm's emissions are in what's called Scope 3 emissions, which are the third parties moving your goods around between you and your suppliers. And that's the biggest part of a firm's emissions according to most studies. So how to even collect that data is still being figured out. Those products are still in the offing. And I think that's kinda where this industry goes next.

- We have been speaking with David Correll, research scientist and lecturer at the MIT Center for Transportation & Logistics, co-director of the MIT FreightLab, and the principal researcher on the annual State of Supply Chain Sustainability report. Dave, thanks for joining us again. I'm sure we'll have you back sometime soon.

- I hope so.

- Let's leave with sort of what's next. So what do you do with this report now? It is available digitally, sscs.mit.edu, where it's available with the digital interface and then also downloadable as a PDF. What do you do next with this piece? Or what can other folks do with it?

- I do exactly this. I take it out into the world and socialize the ideas, see where we got it right, see where maybe our interpretation was missing something, and hopefully someone in the audience of, you know, this audience or the ones that I have coming up will point out what they think. So right now I'm just in the mode of sharing this with the world and seeing what the world thinks of it, and we'll report back what the world thinks of it next time we chat.

- And with that, you have been listening to MIT CTL's "Supply Chain Frontiers" podcast. I'm Benjy Kantor. Dave Correll, thank you for joining us. I really appreciate it.

- Thank you.

- Thanks for listening to this episode of MIT "Supply Chain Frontiers," presented by the MIT Center for Transportation & Logistics. Once again, the State of Supply Chain Sustainability 2023 is available for free sscs.mit.edu. And to check out other episodes of MIT "Supply Chain Frontiers," visit us at ctl.mit.edu/podcasts. And for more on the center's research, outreach, and education initiatives, visit ctl.mit.edu. Until next time.