alt.hn

3/19/2026 at 5:52:11 PM

Connecticut and the 1 Kilometer Effect

https://alearningaday.blog/2026/03/19/connecticut-and-the-1-kilometer-effect/

by speckx

3/19/2026 at 8:46:27 PM

Two concepts that help explain the original article are Diffusion of Innovations and Social Proof.

Diffusion of Innovations is a widely cited theory explaining why people do or don't adopt any kind of innovation, from boiling water to eating limes on British ships to installing telephones. The concept of innovators, early adopters, and late adopters comes from this theory. More relevant to this post is that this theory posits five factors contributing to adoption, one of which is Observability: you can easily see other people gaining benefit from an innovation. The more Observable an innovation, the more likely it is to be adopted. https://en.wikipedia.org/wiki/Diffusion_of_innovations

The other is Social Proof. Seeing what other people are doing, especially those that are similar to you in some way, can help steer your behavior, often in subtle and unconscious ways. There are studies about how simple signs like "people who stayed in this hotel room re-used their towels" or "most of your neighbors are reducing their electricity usage too" can shift people's behaviors, even without people explicitly realizing it. https://en.wikipedia.org/wiki/Social_proof

My colleagues and I used these concepts in several pieces of research on what we called Social Cybersecurity (joking that the term "Social Security" was already taken). The insight we had was that cybersecurity has very low observability, making it hard for innovations to diffuse through one's social network. That is, I don't know what your cybersecurity practices are, and vice versa, making it hard for best practices to be adopted.

One intervention we did was a large-scale intervention on Facebook to improve observability, showing that simple messages like "108 of your friends use extra security settings" did increase clickthru and adoption rates of those settings. https://dl.acm.org/doi/10.1145/2660267.2660271

We also have many other studies along similar lines, e.g. many triggers for talking about and adopting security are social in nature (https://www.usenix.org/system/files/conference/soups2014/sou...), that security settings that are more social in nature are more likely to be adopted (https://dl.acm.org/doi/10.1145/2675133.2675225), and more.

by jasonhong

3/19/2026 at 9:28:10 PM

Nearly 20 years ago after reading Diffusion of Innovations I decided to use everything in the book. The company ran off a few svn servers (formally cvs) and so I ran a handful of Git courses at my work to help us ultimately migrate to Git (this was early days of Git). I explicitly tried to find folks not just near me, but physically around the office building across all of the floors, teams, and orgs. They were my early adopters and when random folks would come to me either curious or for help I would bring them to the "local" expert and together solve their problem, from there they had a local expert and little hubs sprung up. We had the standard svn => git mirror going when the time came to convert to Git full time in the office it was very painless and a complete success.

I was too young to understand that this is how you run a successful "transformation project", I simply was having fun using every trick from that book and done the same playbook a number of times over my career.

by r0ze-at-hn

3/20/2026 at 12:12:58 AM

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by aaron695

3/19/2026 at 8:08:07 PM

Kind of reminds me of "nucleation sites" in physics.

I think one factor that's missing from the explanation is the extensive media and political coverage that solar panels got: There are probably very few people by now that don't know what a roof solar panel is or who don't have an opinion on them.

So my guess is that most of those neighbors who "suddenly" decided to also get a panel, were already interested or at least curious about getting one. (In the sense of "I should totally be getting one some time, but I have no time/now idea how to start/other things are more important/etc")

Maybe the early adopter was then what changed peoples' stance from a vague idea to a concrete plan.

by xg15

3/19/2026 at 8:14:04 PM

How about an alternative explanation?

What if a substantial amount of local solar contractors are doing door to door sales? Or other locality/proximity based sales (signs, driving a car with ads on it, and the like?)

by dragontamer

3/19/2026 at 10:14:46 PM

Is there evidence for this?

by 4ndrewl

3/20/2026 at 12:42:28 AM

I'm writing this from CT. There are absolutely door to door solar salespeople (they don't work for the manufacturer, they work for a local distributor/installation service), and they absolutely tell you how many people in your neighborhood have bought from them.

They ride around on segways here.

by kylecazar

3/20/2026 at 8:17:17 AM

Thank you. I'm not from the US and I had no idea door-to-door sales were still a thing, let alone for significant investments such as solar.

by 4ndrewl

3/19/2026 at 10:23:03 PM

I worked at a company that made a product just for this purpose: making estimates for solar panels for door-to-door sales. It was pretty popular.

by cyberax

3/20/2026 at 6:58:05 PM

There are a number of companies that specialize in using an in-person, in-home encounter to put pressure on people to make poor purchases decisions, enough so that many states have implemented buyer’s remorse laws.

by NetMageSCW

3/19/2026 at 9:57:16 PM

I wonder how effective the UK "green flash" plates (https://www.gov.uk/government/news/road-to-zero-in-sight-as-...) have been at EV marketing. I'm making a habit of looking out for them since I'm considering getting an EV myself.

Nobody on our street has one. I wonder if I get one it will spark a trend.

by pjc50

3/19/2026 at 7:24:38 PM

> People who prioritize their health are more likely to have friends who prioritize their health. And so on. > > We become like the people we choose to be around.

I'm not convinced that that's it. It's more likely that the first person who got solar installed talked to their neighbors about it, and the neighbors were convinced. It's not like after you move to a neighborhood, you're really choosing anything after that point about your neighbors.

by pavel_lishin

3/19/2026 at 7:30:28 PM

You're not actually disagreeing with what you've quoted. Learning about things from those you are near to is one mechanism for we become like those we choose to be around.

by Bjartr

3/19/2026 at 8:09:01 PM

Whether solar is economically reasonable is a matter of the variables of your location. You need strong retail power parity laws, for example. If solar makes sense for one person it makes sense for the other people in the area. Why does there have to be a “catching on” effect?

by hyperhello

3/19/2026 at 9:15:37 PM

Theoretically, if solar did not make much economic sense at all, it would be purely a signalling thing. And those kind of things do spread by the ”catching on” effect. People might then get solar panels just to be seen as the kind of people who have solar panels, i.e. not the wrong kind of people.

by teddyh

3/19/2026 at 10:23:04 PM

Good point.

by hyperhello

3/19/2026 at 8:48:20 PM

For solar panels, many people might be interested but also concerned how they look. When another neighbor gets them, people will get used to how they look, realize it’s not so bad, then be more likely to get them.

I don’t think the final conclusion necessarily follows, not with this example. Solar panels are big and obvious on top of the house. It’s not the same thing as other types of values spreading through a community. The house of a healthy person isn’t any different than that of an unhealthy one.

It could be simply that the door to door solar panel salesperson was covering that 1 km area.

by orev

3/19/2026 at 9:31:35 PM

> Early adopters of solar panels tend to be people who are interested in innovative technology, who find an installer they trust, and who think having solar panels will benefit them.

Also, conspicuous conservation, people like to signal how green they are: https://www.sciencedirect.com/science/article/pii/S027249442...

by youknownothing

3/19/2026 at 8:42:53 PM

Hmm, this actually could have policy implications. If one wants to subsidize a new technology and allocated a limited budget often the first movers are getting it and those first movers may be clusters which is not ideal driving broad adoption. So creating very small geo buckets for adoption oriented subsidies would make sense.

by heisenbit

3/19/2026 at 8:14:30 PM

Some of it may also be neighborhoods where solar contractors went door to door selling the systems. Even if you don't buy from that salesman you get the numbers in your head and start to realize it isn't some exotic tech for elite weirdos.

by jandrese

3/19/2026 at 8:49:02 PM

My sister was just such a representative going door to door in Connecticut. This was likely a factor. The southern coast of Connecticut, being in the shadow of New York and thus dense with rich exurban homeowners, is a prime market for such contractors.

by bitwize

3/19/2026 at 7:52:00 PM

A short and sweet message in this little learning of the day post. You tend to learn from your geographic neighbors. It makes sense! Can we see the same thing for ebikes, and low water lawns?

by skyberrys

3/20/2026 at 12:51:03 AM

>Early adopters of solar panels tend to be people who are interested in innovative technology, who find an installer they trust, and who think having solar panels will benefit them.

I'll bet early adopters of solar panels tend to be people who calculate the fuel economy of a car before making a purchase decision, people whose, damn the paperwork, ears perk up at the idea of a rebate whether from a corp or the govt, people whose enjoyment of a bath entails thinking about how cheap the hot water was.

by fsckboy

3/19/2026 at 7:32:20 PM

This reminds me to get solar.

Proximity is not just geographical.

by worik

3/19/2026 at 6:57:17 PM

Somewhat analogously the best predictor of if I read a book on a given day is if I read the day before, I'd guess.

by grantpitt

3/19/2026 at 9:39:40 PM

It's cool to see CT mentioned on HN. I haven't seen any mentions until today.

My family has installed solar on every house we've lived while there. There is a strong economic incentive. CT has some of the most expensive avg. electricity cost in the country (a few cents cheaper than California for comparison). And Eversource, the utility company, is universally hated. Most people want to switch from their terrible service and are looking for any reason to.

by kalinkochnev

3/19/2026 at 9:51:22 PM

CT is too far north for solar PV to save on the CO2 generated. The solar albino there is less of .25.

by hunterpayne

3/20/2026 at 3:51:23 AM

No, Hartford is at the same latitude as Barcelona, Rome, and Beijing. It's not too far north.

by kibwen

3/19/2026 at 8:58:16 PM

Assuming this is as reliable effect as implied in the article, a cost-effective method to jump start solar install rates would be to map out roughly 1km wide zones and provide a high and declining subsidies for the first/early people to get solar installed. E.g., go to map and find your house and zone, if five haven't signed up in your zone, it's open, the first to put deposit on install contract gets a $15k subsidy when install complete, $12k for second, $9k for 3rd, $6k 4th, $3k 5th. Adjust zone sizes and/or subsidy amounts for subsidy budget, population density, etc.

Probably a lot cheaper than a $3k subsidy for everyone, as this is only 15 $3k subsidies in each zone. Also probably a lot better to do this with everyone gets a $2.5k subsidy and the first five get the higher incentives.

by toss1

3/19/2026 at 11:44:39 PM

So give free solar to selected homes with 1 km spacing. Either the government or solar companies should be willing to sink this cost in order to get the additional business.

by dheera

3/19/2026 at 8:25:27 PM

a/k/a "Keeping up with the Joneses"

by SoftTalker

3/19/2026 at 11:14:16 PM

We have solar. It so happens the people next door also do, but we didn't know that when we started. In the almost two years since we added ours, no one has asked about them, possibly because our house is on the highest hill in the neighborhood and they are not easy to notice from anywhere surrounding. A side benefit it learning that Generac's support is as crappy as their hardware is good, but we refused to give any money to Tesla.

by theturtle

3/20/2026 at 1:23:08 PM

If you are curious to know you could test that out. Something like, can you believe how hot it is today, I'm so glad I got those solar panels installed, they will save me a ton. The response will be either Oh really, i never noticed. or yeh, but the cost too much. If you are the green type you could could also use that as a sales pitch.

by Shitty-kitty

3/20/2026 at 12:44:24 AM

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by abhishekmaan_19

3/20/2026 at 12:44:34 AM

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by AiStockAgent62