Des Moines Airport Advisory Committee — July 30, 2026

**Bogen** [0:00]: I don’t think we’re going to be doing any votes — I really think it’s a discussion about whether to support this. So, Joe — you may have spoken to Joe already. Let me briefly go over what I think we can do at this meeting, which is what Joe asked us to do. About a week or two ago, Joe presented me with a study that looks at home valuations and the impact of aircraft noise on property value. The study uses a particular methodology — a hedonic methodology. I appreciate that I’m no real estate expert, but I did use some of the analytics from the study to derive numbers specific to SAMP. With SAMP, in the 65 DNL, you can use the results of their methodology and translate that into terms specific to SAMP, and then extrapolate past 65 DNL, out to where noise levels are above 55 — which is about the level I can detect.

**DeLacy** [1:37]: Right — because you said, if you’re on a busy street it might be in the 50s.

**Bogen** [1:44]: Yeah. Once you get above around 50 to 55, you can’t really distinguish aircraft noise from traffic and other community noise. It becomes very difficult to tell what’s what. This study looks at property values in one-decibel increments of DNL. DNL, as you know, is a time-weighted average, and it moves very little — even with SAMP, even with a lot more aircraft, which we expect, you still get very little movement. It’s very insensitive. I used that to calculate the valuation effect on homes. This may not be the only appropriate methodology — there are others —

**DeLacy** [2:37]: No, but it’s a good one, and I’m familiar with it. I’ve done hedonic modeling; it’ll be very helpful.

**Bogen** [2:45]: So I came up with a number. If you read the report, I gave a figure for SAMP of around $12 million. It’s a very low number — a couple thousand dollars per decibel of increase. And that increase is actually tied to the improvements you get with PBN-type methodologies and technology improvements. They did this at O’Hare, and at Logan, and found the same kind of correlation, but much stronger. The report is really weak when it comes to Seattle. It didn’t look at some of the parameters you’d use for house valuations — like resale values of the same home, which I think is very important for understanding the appreciation rate. That piece was hard to come by, because there wasn’t enough data in their data set.

**DeLacy** [3:43]: Believe me, that’s the bugaboo of these studies. You’d like to have nothing but paired sales — the sale price before, say in 2012, and then in 2020 when they moved. That’s the difference. And what is that delta compared to what it normally would be in the area? A hedonic model is best to test that. But the numbers are never very impressive — usually they’re rather timid. There is significance, from what I read, though.

**Bogen** [4:22]: Right. So using the data they did have, I came up with about $12 million — only about a $2,000-per-house impact for a one-decibel increase, and we’re only getting half a decibel. It’s always less than 1.5. So I drew an analogy and got some numbers: it went from $12 million to $46 million by 2037. If you expand it out past 65 DNL, with contours I interpolated, you can get to numbers like $150 million, easily.

**DeLacy** [4:59]: And the other thing that generally doesn’t get taken into account is marketability and time on the market — what really happens with homes impacted by something like this. They just don’t sell; they get taken off the market. The same thing happens with spikes in interest rates. We saw it in 2008 in the crash — homes just don’t sell. A house you’d expect to sell in 90 days doesn’t. That can be measured, but it’s more complex.

**Bogen** [5:44]: So what I did was find communities where I have data available. The sensitivity I can get is only down to the zip-code level — I don’t have it by community. And unfortunately one zip code —

**DeLacy** [6:00]: One zip code for the whole area.

**Bogen** [6:05]: Right. It extends out past Des Moines and into other areas. I tried to use a control neighborhood — Shoreline, Kirkland — where there’s no aircraft-noise impact, and contrast that with places that do have it, particularly under the approaches where it’s most significant: Des Moines, maybe Federal Way, then up north, and certainly SeaTac. But there’s not enough sensitivity in the methodology available with this study. So I think we have to decide whether we should use this study to make some comments. That’s what Joe wants to know.

**DeLacy** [6:49]: Yeah — because it’s a strong argument.

**Bogen** [6:52]: Here’s what I think. What the study shows is significance. For all the reasons you cite, it can’t really plumb the depths — there are a lot of issues that don’t show up, like time on the market, homes getting pulled off because they can’t sell. But it is significant, and it’s significant in comparison to similar communities outside the impact area. I saw a weak correlation in this study. The things missing that would make the methodology stronger — to support the argument that there’s a correlation between aircraft noise and home appreciation in affected areas, particularly with SAMP, since it’s not short-term; SAMP allows for increased growth capacity — so I tried to model just the SAMP piece, to see where that would land, because that’s specific to the DEIS. You’ll notice I haven’t been able to find much documentation on house-value appreciation and SAMP — you don’t see anything, really. So what I further did was an analysis of home-price appreciation. I pulled what you can get for free — off Redfin — and looked at different communities using real numbers, not the study’s complex methodology, just appreciation numbers. In some communities there’s a few-percent loss in appreciation, but other communities did quite well — like Des Moines — contrasted with communities not impacted by aircraft noise. Using just Zillow and Redfin data, you also see a correlation between the price of the home and the appreciation rate. Things like price per square foot have to be considered. More expensive homes seem to be appreciating at faster rates.

**DeLacy** [9:32]: That’s right.

**Bogen** [9:37]: So you have all these caveats that are difficult to untangle. If I had good data based on second sales, resale values — and I don’t have that by zip code. Do you have that?

**DeLacy** [9:53]: Where we’re going with this, I think, is: there’s evidence of significance that they didn’t track. It’s beyond the scope of our advisory committee to do the work. You’ve gone well over and above what any airport committee could come together and do. What we’ve done is enough to cast doubt on the metrics they used — and it goes to the issue that we have a significant impact, which we haven’t plumbed, that would be done by a subsequent study. If you wanted to put hard numbers on it, you can’t expect to do that with what we’ve done. But there’s enough literature out there to suggest there’s an impact, coupled with the anecdotal experience of the real estate community: if you ask anybody why homes sell for less in Des Moines than in a comparable community out of the flight path, they’ll tell you it’s the airplane noise.

**Bogen** [11:07]: But you have to be able to back it up with numbers.

**DeLacy** [11:10]: Well, I think what’s here, Jeff, is enough. It’s significant, based on analogizing with these studies. No one actually studied the issue here at all.

**Bogen** [11:25]: Yes, it’s not covered. I have not seen any formal public documents on house valuations and aircraft noise published, that I found. This one study covers a little bit of it, but there are many derivations in it. The raw appreciation numbers on second sales I’d think would be easy to get — but I don’t have access; it costs money to get that level of sensitivity.

**DeLacy** [11:57]: That’s exactly it — we should charge for it. Now, the problem with resales — as an appraiser, having dealt with this as an expert on both sides — resales are difficult, because there are so many variables, particularly the more you get into custom homes. I’ve had some luck where, if you were comparing two subdivisions built by the same builder at the same time, and you wanted to isolate and measure the impact of, say, a substation out front of one and not the other, you might be able to isolate and quantify the impact, because you can hold everything else equal. The hedonic model attempts to do that. But again, all it can tell you is whether a number is significant, and how large it is. You seldom find a measure much over 5 or 10%. And then, is the correlation strong enough for significance? So I think what we say is: these are studies that were not considered; they suggest there’s significance and adverse impacts. If you really wanted to find how much, we ought to commission the study to do it. It can be done, but it would take time or money. I’m not going to volunteer us for $50,000 of work, but that’s what it would take.

**Bogen** [13:48]: Is there data available that shows resale value — resale, over a particular community?

**DeLacy** [14:04]: Let me tell you how you do it. You’ve kind of got to do it by hand. We’re a disclosure state, so you’d select a couple of communities. You’d say, we have Des Moines — and what are our test communities? You might go to Normandy Park, which is outside, though it’s not that effective — there aren’t many homes there. You’d have to be careful. While you might want to compare the upper-end custom homes, you’d want to focus on homes under, say, the million-dollar — if not $800,000 — threshold. Look at that body of sales. The good news is most of this area developed in the last 30 or 40 years. You’re not factoring in — I looked at stuff up in Everett on a project where they were using homes built in the ’20s alongside new homes in the same area. That’s great for charm; it’s not good for analytical comparison. You want really bland subdivisions. So it would take that, and then going into the county — you could get a list of properties within an area and run the whole area. You’d run a spreadsheet, look at the sale, and sort.

**Bogen** [15:45]: Is that data publicly available?

**DeLacy** [15:48]: Yes, it’s publicly available. But you’d have to have somebody go in and do the work.

**Bogen** [15:53]: So it’s not publicly available online?

**DeLacy** [15:58]: It is online, but you’d have to do the work. Nobody does the pairing — that has to be done by an analyst. But the sale data absolutely is available; it’s all public record. You just have to define the parameters. The assessor cards are available on every residential property — it’s used for the ad valorem assessment of property values.

**Bogen** [16:19]: So this is an assessor property database?

**DeLacy** [16:29]: Yes, and it’s all King County.

**Bogen** [16:30]: King County. Okay, so it’s available.

**DeLacy** [16:33]: Yes, it could be done — with a methodology that looks at second sales. Just using the median home price isn’t sufficient to gain enough insight, because custom homes screw it up as you get into the higher end. Somebody buys a home, does add-ons —

**Bogen** [17:04]: I get it. Look at Lower Woodmont — there are some new homes, but everything is custom; everyone goes in and trips it out, adds $10,000. I understand all these little —

**DeLacy** [17:16]: So where there’d be fruitful data is all the areas where subdivisions were developed around the same decade, of the same quality — fundamentally three-to-four-bedroom homes, two-car garages. Those you’d find in very similar neighborhoods to those built in Des Moines, in peripheral areas.

**Bogen** [17:42]: Yeah, that’d be our control. So I do think it’s a more engaged task than certainly I have the expertise to do, because there are all these things we’d need strong arguments for to make the case.

**DeLacy** [17:57]: There are nuances in neighborhoods, and a residential appraiser would understand that implicitly — it’s part of what they do. But appraisals are very much micro-economic studies; we want to do something at the macro level, and most appraisers could help you with nuance but not with the macro you need. I’ve actually run consortiums that have done this before. We did it back in the ’80s to show that prices in Multnomah County, Oregon were adversely affected by creative financing, and we got the assessor to reduce values by 10% — based on a hedonic study across geography, working with the realtors. They just didn’t want to spend the money to do it. It can be done. We’re talking about $50,000 to $100,000. You could have an academic do it — run a stats department and get somebody.

**Bogen** [19:04]: Considering the scope of SAMP and the economics of it, why do you think this hasn’t been done? I don’t think it has — but why hasn’t it? And why isn’t it a fundamental piece of the EIS?

**DeLacy** [19:28]: It should be. These days, property-value impacts are usually only required at the high level — for the siting of facilities by a siting authority. I’ve done published work, on the public record, on the potential impacts of wind farms on property values — and the only reason I was brought in is that it was required. Most rural jurisdictions, when zoning was employed for electric energy-generating facilities to be on ag land, just didn’t know about it — it wasn’t there. What we’ve seen here, *[name unclear]*, they’re following a road. These things happen all the time. They’ve got their regs; they don’t go beyond the regs. If it wasn’t in there, the box isn’t near the check — they’re not asking. So that’s one of the things this advisory committee can help bring home: hey, guys, there’s a very important impact here that the study isn’t addressing. It’s just glossed over. And there are ways of getting it right. So I think it’s an important topic.

**Bogen** [21:05]: This is the reason we’re doing this — Joe asked, should we pursue this? He’s asking, can this group pursue it? I took a first cut, and then found there are many other issues. If I want to be accurate and specific, it’s hard to do without the right data.

**DeLacy** [21:27]: Professionally, I know where to do it and how — it’s a question of X number of hours. It’s absolutely available; it just hasn’t been mandated, so they haven’t looked at it. What we could do is say: there’s demonstrable evidence, with the hedonic studies in comparable areas, that suggests this should be done here. There’s anecdotal evidence that Burien and Des Moines are disproportionately impacted, and have been cumulatively for the last 30 years, and this master plan isn’t complete without addressing it. They’ve held things up — the zoning change in Seattle — because a judge decided they hadn’t addressed the impact on orcas. For a high-rise, what’s the impact on orca whales? Really? But this is much more tangible and real, and they just didn’t consider it.

**Bogen** [22:45]: The purpose of this meeting is really to ask and provide feedback to Joe about where we want to go with this. So we have evidence, through the study, of a weak correlation — with all the caveats about missing geographic sensitivity, because they didn’t do it. Of course there’s weakness, but there’s a real problem, and they haven’t tested it — just like your arguments about health. We really think there’s a problem, but they didn’t bother to test it. “Move along, nothing to see here.” The same is true for property.

**DeLacy** [23:32]: But in the case of health, we do have some conflicting reports. In the case of home appreciation, there’s data — I would think, with enough specificity and sensitivity to the areas and type of homes, one could make a very strong case and just say that’s what it is. Whether or not that affects how SAMP is rolled out, and whether it’s included — it would be nice to be able to support that argument.

**Bogen** [24:04]: Yeah — I don’t know if that’s going to feed into the mitigation piece. Whether this is a question of reducing assessed values by some kind of exemption, and then, secondly, having some kind of gate-receipt or dedicated revenue targeted to the communities, so we can compensate in other ways, since we can’t help the homes directly. But without stronger data than just this study, I think it’s hard to make the argument without doing that additional real work.

**DeLacy** [24:44]: I agree with you. We don’t have the time, we don’t have the means, and it wasn’t within our charge to go hire a consultant for $100,000 to do this. All we can do is raise the red flag and suggest that’s why we’re concerned about SAMP: they haven’t considered adverse impacts on property values. We have evidence that it’s significant; we’d like to quantify it, but we don’t have the means. That’s what I was hoping — if we had Steve here, we’d have a forum where we could make a resolution to city council to pass this on. Or, as the airport advisory committee, we could say we’ve found, as a group, and make a positive statement — not be timid and say we don’t have enough data. Of course we don’t have enough data; we weren’t given the resources to get it. But we’re expert enough to know there’s a problem here.

**Bogen** [25:53]: So, really, to answer Joe’s question — I don’t think we have to take a vote. I think we can give that feedback to Joe and tell him what we’re suggesting: if he wants to pursue this and include it in some form — either as a comment, or as feedback to the people working on this — this is a valuable study to start looking at. It would add value to the things we really care about in this community. So — what possible impact can our advisory board have on SAMP going forward? Ultimately SAMP is voted on by the Port commissioners.

**Deming** [26:52]: Correct.

**Bogen** [26:53]: So our job would be to say, hey, guys, it’s not complete.

**Deming** [27:03]: That’s right. You already went to council with the letter, but you decided not to move forward with it. You’d already decided to go with individual letters, so you could add something with this language to your individual letters.

**Bogen** [27:19]: Yeah. I still think it would have been a lot more effective to have something from the whole committee — that we’ve decided, and we don’t disagree with anything — still going with something substantially conforming to what they already approved.

**Deming** [27:35]: Yes, you still have that choice. They already authorized you to write a committee letter substantially conforming to what went to council. But you chose not to — and they’ve extended the deadline, so you still have time.

**DeLacy** [27:50]: Well, then I think we should go with that letter. We’ve all given individual input — Jeff has, I have, Joe has. Why not do something as a group? We already had the authorization; why quibble with it because we don’t have the means to do it? Jeff, of course, your issues — but that’s not our role. We’ve raised the flag. We’re not the hired consultants to resolve it.

**Bogen** [28:23]: We discussed at our last meeting that there’s some sensitivity about ensuring the council has an opportunity to review the complex issues I raised, so we chose not to include those, and to allow the council to read them and do what they’d like. Are there other issues, outside of what I’ve written — including maybe this issue about home property not being addressed? Would it be okay to mention it, since we’re not being specific?

**DeLacy** [29:11]: No — nor can we be. But it is significant. It’s really a deficiency in the inclusion of important issues that should be in the environmental impact statement, affecting a large number of people — at least 9,000 or 10,000 at minimum — regarding the value of their property. They don’t include it. They could have done a study, which we’d critique and have issues with, but they haven’t even looked at it.

**Bogen** [29:45]: Yes. I don’t believe there are any words at all on property valuations. So that would be a recommendation — to proceed with that study, for completeness. Can we do that, Rebecca?

**DeLacy** [29:59]: But how do we articulate what Jeff has raised? You’re suggesting putting it out as a letter. Is the city going to be writing the letter?

**Deming** [30:13]: We have someone who will be writing the response.

**DeLacy** [30:16]: We could suggest that property-value evaluations should be included as one of the topics, without presenting supporting data — except to mention that there are actual studies.

**DeLacy** [30:33]: Well, that *is* supporting data — that’s why we’re raising the issue. There have been legitimate concerns raised in the literature. It hasn’t been refined to where we are, but it supports what we anecdotally understand on the ground.

**Deming** [30:50]: Yes. And I believe they already have that study. The legal team has it already, and we’ve already hired consultants to look at this issue.

**Bogen** [31:01]: So hopefully the consultants should be doing something like this. If they’re going to use the study —

**Deming** [31:09]: I’m not sure if they’re using that study specifically or doing their own.

**Bogen** [31:14]: Who is it — Northwest? Leland? Where are they?

**Deming** [31:20]: I assume Seattle, but I’m not sure. There used to be Portland City—

**DeLacy** [31:27]: Yeah, I doubt they’re going to derive dollars from this. It’s extremely difficult to take this study and derive Portland-specific information. They’re out of Portland.

**Bogen** [31:43]: Okay, so they’re in economics.

**DeLacy** [31:48]: Yeah, and this is basically economics. And you don’t need a whole lot. This is quite different from epidemiological health studies — you don’t need to know a lot about noise to do the analysis of home-value capitalization. So it’d be a good area for them to look at.

**Bogen** [32:12]: And I think we all agree it’s an important issue that should be mentioned. So, Rebecca — Leland is doing a property-value impact study, as far as you know?

**Deming** [32:28]: No. They’re writing a memo to assist the city in responding to SAMP. They’re not doing their own full study — they’re reviewing the EIS to respond.

**Bogen** [32:46]: Right. Is there any reason we can’t, as the airport advisory committee, say: please look at your property-value impacts, since they’re not doing that specifically?

**Deming** [32:58]: Again, to do anything as the airport committee, it needs to go through council for approval. But as an individual, you can write anything.

**Bogen** [33:08]: I think you gave us a good preview of the kinds of things that team is looking at. It’s quite specific to projects — particularly environmental impacts where there are deficiencies or a lack of clarity on some of the programs — and some very real ways they’re digging in. The presentation Rebecca gave was quite involved; there’s quite a bit of work in that area. But property value — I didn’t get into that part.

**DeLacy** [33:41]: Do we know who’s working on this at Leland? Are you in contact with Jennifer?

**Deming** [33:50]: Jennifer is one of them — Shook. I’d have to look at who the other person is.

**DeLacy** [34:00]: Is there any reason we couldn’t contact them?

**Deming** [34:07]: They’re contracted through the three cities, so that may not be the appropriate connection. But we can certainly get feedback to them indirectly. Once it’s all done, it’ll all be public — all the memos and everything.

**DeLacy** [34:29]: Is there any reason we couldn’t get some of what Jeff has done and ask them to look at it?

**Deming** [34:32]: Yes, I’m happy to pass along whatever you want me to pass.

**DeLacy** [34:37]: Well, why don’t we do that, Jeff? I know Leland — they have the study.

**Bogen** [34:44]: They have the study, but they don’t have my analysis of it. This is why we’re having the meeting, really, Bart — because the methodology in their study can be criticized. It’s not strong evidence of a substantial impact to home valuation, in my opinion. This is not something to be published yet; it’s missing the sensitivity to draw the conclusions necessary. It’s stronger for Chicago and O’Hare; it’s extremely weak right now for Seattle, if one were to use its analysis and methodology.

**DeLacy** [35:30]: Well, is there any reason you couldn’t say exactly that, and submit it to them to look at?

**Bogen** [35:38]: That’s what I wanted to talk about with this group.

**DeLacy** [35:42]: I think you should. My answer is yes; I think Joe’s answer is yes. So the question is how do we do that? How do we know anybody’s going to read what Jeff has written — his commentary on property-impact values — with the city’s consultant?

**Deming** [36:07]: Again, there’s city process going on; they’ve hired the three cities. I’m happy to forward it on, if that’s what you want. In terms of them reading it — through the court, they’re required to read every comment letter. But I’m happy to talk to them.

**Bogen** [36:32]: I don’t think my analysis — Joe sent me a study; I hadn’t read it. Joe asked, does this study support home-appreciation value losses due to aircraft? Does it support it? So I did an analysis of the report to see if it does — because you have to be statistically minded to take that report and say something specific about Sea-Tac. That’s why I wrote it. There are things they’re missing that should be included, and that’s what the discussion was going to be about: should we try to include those things? What I was missing was home valuations in the areas of the 65 DNL — which, you’re telling me, is more difficult than I understood. I already had some challenges getting the data, and then appreciated just how much is missing to really draw conclusions.

**DeLacy** [37:52]: It can be done, but you have to get into the numbers better. Public multiple-listing data also fine-tunes those numbers — that’s a second source. It’s proprietary; we have access to it, most realtors do. You have to dig in. What we all need to do is put a red flag up and say: there is easily attainable data, which has not been addressed, regarding potential adverse impacts on home values suffered by those communities within the DNL area. That was not considered.

**Bogen** [38:52]: Yeah — I can draw them a picture of what you do. Whether anybody would pay attention if we spent a week of our time — we could find volunteers to run down and pull this stuff together, but that’s what the consultants have been paid to do. Our job is to say: have they gone far enough? The answer is no. And the city council — these are their clients — they should be asking these questions. That’s why they have citizen advisors with some degree of expertise to help out. They can’t expect the mayor’s HR person to know this stuff. So they have a study; they can use it. I took a look at it — I think it’s difficult to derive strong correlations with this report. I don’t want to work against them; let’s let them do their thing and use whatever documentation they feel is appropriate.

**DeLacy** [40:12]: Well, why can’t we put a red flag up and say we don’t think it’s gone far enough?

**Bogen** [40:17]: I think there’d be ways to do it.

**DeLacy** [40:22]: Yeah, that would be good feedback.

**Bogen** [40:22]: How do we get that information across? Who do I communicate that to?

**Deming** [40:28]: There’s a reason we hired them — we also felt the EIS didn’t go far enough. That’s why we hired Leland in the first place. So we felt the same way. I’m confused on what you want us to pass off.

**Bogen** [40:39]: I want them to dig deeper into housing values using the multiple-listing service and the assessor records, where they can refine market areas and make better comparisons. I don’t know what they’ve done, but if that’s all they’re using —

**Deming** [41:02]: That’s not all they’re using.

**Bogen** [41:02]: Well, what are they using?

**Deming** [41:05]: They’re using all the city’s GIS data, all the DNL layers — lots of stuff.

**DeLacy** [41:11]: They have economists — they all had degrees from the same place I did, Portland State, and University of Oregon. That’s where they all come out of. But they don’t necessarily do the micro-analysis you need to dig into that.

**Bogen** [41:29]: Where I think we’re getting a little hung up is that all the issues we’re bringing up — health, noise, pollution — we want to make sure the Port sees those, and we also want to make sure the legal folks are working those issues. We don’t have feedback from them that they are, but I think they’re working professionally on it. They’re a contractor, so we really shouldn’t be engaging directly with them at all — that needs to go through the cities, who are working with the contractor directly. So we should provide our information to the cities; the cities can pass feedback to them if they’d like. That would be our advice. In our council, it should come up through our group, and Joe can simply say, make sure they look at this kind of stuff.

**Deming** [42:44]: I can tell you that one of their points — we’re still working through this, so nothing’s final, and it’s not a long document — but one of their bullet points clearly says there’s significant academic literature pointing to the direct effects of noise on property value; however, the SEPA DEIS does not adequately assess the fiscal impacts of this expanded noise contour.

**Bogen** [43:04]: So it sounds like they have that information — like they pulled it right out of the study. And this is one sentence on a 22-page document.

**DeLacy** [43:19]: Indeed. And if they want to make that case strong, they’ll do exactly what we’re suggesting — go to real numbers and figure out what the appreciation losses, if that’s what they find, would be. Hopefully they’ll take a crack at it.

**Deming** [43:33]: It looks like they’re citing eight or nine different pieces of literature as well, not just the one.

**DeLacy** [43:43]: All right. So then you could get more specific, local — you could actually put real numbers on that, but that’s beyond the scope of what they were asked. I don’t know what they’re going to do. They might very well be doing the work necessary to make a first cut.

**Deming** [44:11]: Unfortunately, the document’s not public yet, so all I can give you is generalizations.

**DeLacy** [44:17]: But to make a really strong case, you’ve got to have very sensitive communities — control communities — and compare and contrast, under the flight paths directly, those particular homes to the north and south of us, then look at some similar communities and do that work. And that’s a lot of houses you have to manually drop into the 65 DNL. There’s probably no quick tool to do that.

**Bogen** [44:41]: Well, we have the layers for that.

**DeLacy** [44:48]: Looking for paired sales — you call them down, and not all will work; they’re more anecdotal than statistically significant. But there’s a homogeneity to many of the Des Moines neighborhoods directly impacted that you wouldn’t find closer to the water. I’m confident you could take those homes — built at the same time — and look at how they’ve been bought and sold. Why are property values demonstrably lower in Des Moines than in comparable areas?

**Bogen** [45:43]: Yeah, they are.

**DeLacy** [45:43]: You could see, beyond median home prices, that the appreciation values over the last 10 years don’t move along as Des Moines has. Des Moines has done very well — in fact, as well as Kirkland and Bellevue. But remember, those are average prices, median prices.

**Bogen** [46:06]: Yeah, that’s all these issues around home prices.

**DeLacy** [46:06]: One year you can have a $500,000 home sale, the next a lower class of home sells and values go down — it’s just that the average price of home sold went down. The whole thing can be biased by a large number of less expensive homes. Take the middle price and you’re pulling it the other way. It all has to be normalized.

**Bogen** [46:34]: And Rebecca — maybe that’s enough. They’ve acknowledged a significant impact when they said an impact hasn’t been addressed; there’s evidence it does have an impact.

**Deming** [46:44]: Yes, it sounds like that’s going to be included in some form, and they’ve identified it. The only thing we can add is perhaps a methodology they might want to include, if they haven’t. We don’t know the methodology they’re going to use to support that statement. They’ve reviewed the literature, which is part of it.

**DeLacy** [47:11]: Yeah, that’s what you do. If you don’t have data, you look at the literature. If you really want to demonstrate it, you dig in from the data and do your own hedonic model.

**Bogen** [47:24]: They did it. We might suggest, really simply, that since there’s concern about value impacts, a hedonic exercise be undertaken — it could be of value. This study shows there’s value in using this, particularly if it’s done with more specificity. That’s what I found. They can read it if they want. It’s interesting how one comes to conclusions using those models, and some of the deficiencies. Remember, whoever did that was looking at very large, global data—

**DeLacy** [47:58]: Yeah. And we’re talking about Sea-Tac specifically, and what’s happened around it in this community, and SAMP specifically. That’s really where we gain the most traction — to demonstrate that SAMP, just in the 65 DNL, which is the only thing they look at — there is a correlation between aircraft noise, which is measured and acknowledged by the FAA and the Port, because that’s the regulatory area they’re concerned with. They can make statements about just those homes, in just those areas, compared to a control area outside of that.

**Bogen** [48:45]: Yes. And that’s what they should do, and I’m hoping they do. It sounds like they already have enough information and awareness to move forward on some of that. So we could say a few things about the methodology to use, if they wanted to pursue that.

**DeLacy** [48:59]: That would be our expert advice tonight?

**Bogen** [49:03]: Yes. So how do we do that?

**DeLacy** [49:07]: You write a paragraph. You’re our expert — you’re a real estate expert. Do you have real estate expertise?

**Bogen** [49:15]: Not that much, now. I’m good at analytics, but if I don’t have the data, I can’t analyze anything. I didn’t even know what “hedonic” meant before I started. So — seriously, do you want me to? Should I? Who do I address it to, as an additional comment, having looked at some of the background data? Do you want me to pass it on to the consultant?

**DeLacy** [49:37]: You’d write it to me — if that’s what you’re asking.

**Deming** [49:43]: Write it to me, and I’ll pass the information to our consultant.

**DeLacy** [49:47]: Or you could pass it to Joe — Joe is our leader here for the team; he could pass it along. However you want to work it. I think your words probably have the most expertise around the right type of words — short and clear. Let the rest of the experts on the legal teams work it and see where they go.

**Bogen** [50:15]: How do you spell “hedonic”?

**DeLacy** [50:15]: H-E-D-O-N-I — it’s from “pleasure.” It’s basically multiple regression analysis. It’s kind of a black box, but you’re able to assign impacts. For single-family homes, you can say how much of the sale price is explained by the size of the house, how much by the number of bedrooms, by the garage. You rate these characteristics, and you try to get a fairly homogeneous sample — so that everything built between 1970 and 1980 isn’t a big variable — and then you can isolate the unknowns. What we did was ask: how much of the sale price is explained by the creative financing that had been put in place? You run through them all and see what’s significant. Is the color of the house significant? Probably not. But some things are — high correlation between size and sale price, high correlation with date. You’ll have at least eight to ten characteristics like that, and because it’s a multiple regression, you can isolate for something like the rate of financing — or, we could say, airport noise. And then, gosh, 10% of the sale price is explained by *not* being under the airport, because everything else is basically the same. That’s how they work. And think about it in real-life terms — think about when you go to buy a house.

**Bogen** [52:20]: Are we done? Yeah, I think we are. Close the meeting.

**DeLacy** [52:29]: Other comments will just be anecdotal. All right.

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