【Hacker News搬运】Suspicious discontinuities (2020)

hackernews

Title: Suspicious discontinuities (2020)

可疑的不连续性（2020）

Text:

From: https://news.ycombinator.com/item?id=39768860

Url: https://danluu.com/discontinuities/

文章讨论了各种不连续性现象，包括个人财务、税收政策、健康保险补贴、技术、投票、汽车销售、学术研究、药物犯罪、高中毕业考试、体育运动员出生月份、政府采购拍卖、餐厅检查评分和马拉松成绩等。作者指出，这些不连续性可能导致非理想的结果，并提出了通过平滑过渡而不是尖锐阈值来解决问题的建议。文章还强调了识别和解决不连续性的重要性，并鼓励读者分享他们发现的有趣不连续性。

Post by: explosion-s

Comments:

desiarnezjr: DO NOT DOWNLOAD THIS.I downloaded (not Shattered) Pixel Dungeon and then Shattered, and nearly a decade later I'm still playing. In fact it's 70% of my non-work computing time.Not only that Shattered's dev updates often with sometimes great changes.You've been warned.

desiarnezjr: 不要下载这个 我下载了（不是粉碎的）像素地牢，然后粉碎，近十年后；I’我还在玩。事实上；这是我非工作时间的70% 不仅如此；s的dev更新经常会有很大的变化 您&#7；我已被警告。

rjmill: Well, there goes the rest of the week. I don't install games on my phone, but I always give SPD a pass because open source. The first time I installed it, I almost lost an internship because I was too focused on the game. The most recent time I installed it, my wife thought I was cheating on her because I was acting so shady and obsessive about my phone. Don't say I didn't warn y'all.

rjmill: 好吧，这周剩下的时间就到了。我不；我没有在手机上安装游戏，但我总是通过SPD，因为它是开源的。我第一次安装它时，因为太专注于游戏，差点失去实习机会。最近一次我安装它时，我妻子认为我在欺骗她，因为我对自己的手机表现得很阴暗和痴迷。Don；不要说我没有；t警告y；全部的

codetrotter: So after reading the positive comments here I went ahead and bought a copy for iPhone in the App Store.I was hoping that it supports controllers, as i recently bought a pretty neat controller that you plug the phone into the middle of, and you get buttons and thumb sticks on each side of the screen. Kind of similar to the joycons you have with a Nintendo Switch. This controller is PlayStation branded, but produced by a different company that has licensed the right to brand the controller that way.Anyway, I am happy to report that yes indeed this game works with my controller. Left thumb stick moves the character around, and right thumb sticks moves a sort of aiming square around!Edit: the pointer sensitivity was a bit high for me, but it is adjustable in the game settings and after adjusting it it is comfortable

codetrotter: 所以在阅读了这里的正面评论后，我继续在应用商店买了一本iPhone 我希望它能支持控制器，因为我最近买了一个非常整洁的控制器，你把手机插在中间，屏幕两侧都有按钮和拇指棒。有点像任天堂Switch的游戏手柄。该控制器是PlayStation品牌的，但由另一家公司生产，该公司已授权以这种方式为控制器品牌 不管怎样，我很高兴地报告，是的，这个游戏确实可以用我的控制器。左手拇指棒移动角色，右手拇指棒移动一种瞄准方块 编辑：指针的灵敏度对我来说有点高，但它可以在游戏设置中调整，调整后很舒服

Borealid: I'm not really sure what this is doing on Hacker News, but the game (Shattered Pixel Dungeon) is fun.One of the nicest features is that whenever you observe an effect that unambiguously tells you what a potion/scroll does - such as throwing a potion - that type of object is automatically identified for you. In more "traditional" hack games you'd have to write notes yourself even though obviously a thrown potion exploding into fire means it's a potion of liquid fire, right?Shattered Pixel is a good way to kill some time on public transit or similar.

Borealid: I-；我真的不确定这在黑客新闻上做了什么，但游戏（破碎的像素地牢）很有趣 最好的特征之一是，每当你观察到明确地“告诉”你什么是药剂；滚动可以——比如投掷药水——这种类型的物体会自动为你识别。在更多的“；传统的“；破解游戏你；我必须自己写笔记，尽管很明显，扔出去的药水爆炸起火意味着它；这是一种液态火，对吧 破碎像素是在公共交通或类似交通工具上消磨时间的好方法。

jpsouth: I’ve played this for a while, and not to brag, but I’ve got to chapter two on a warrior AND mage.I love the identification process and relatively quick, albeit very tactical if you want, gameplay. It’s my go to iPhone game when on short journeys, mostly because I can just save where I am and pick up whenever without having to remember dungeon layout or potions/food etc.

jpsouth: 我玩这个游戏已经有一段时间了，不是为了炫耀，但我要开始第二章关于战士和法师 我喜欢识别过程和相对快速的游戏性，如果你愿意的话，尽管非常有战术性。这是我短途旅行时最喜欢的iPhone游戏，主要是因为我可以保存自己的位置，随时拿起，而不必记住地牢布局或药剂；食物等。

jjwiseman: I've been working on mapping GPS jamming using ADS-B data for a couple
years, and I'll try to address questions and points brought up here
based on what I know.Relevant previous posts on HN:2022: <a href="https://news.ycombinator.com/item?id=32245346">https://news.ycombinator.com/item?id=32245346</a>2023: <a href="https://news.ycombinator.com/item?id=37868106">https://news.ycombinator.com/item?id=37868106</a>(From my comment on that 2023 post: "Why haven't FlightRadar24,
FlightAware, or any of the other flight trackers done this?")"A single observer can't really say for certain that jamming is
happening; you need a distributed sample from multiple different
sensors over a period of time to have reasonably high confidence."There are heuristics you can use that allow you to make a pretty good
guess about whether jamming is happening based on signals from just
one or two aircraft, and have worked well on GPSJAM for the past
couple years.With regard to localization of GPS jammers, yes you can do direction
finding of the emitted signal directly, but that's easy mode. For a
fun challenge, do it based just on observations of the ADS-B data from
affected (and unaffected aircraft). Here's one approach from
researchers at the GPS laboratory at Stanford, "GNSS Interference
Source Localization Using ADS-B data":
<a href="https://web.stanford.edu/group/scpnt/gpslab/pubs/papers/Liu_ION_ITM_2022_ADSB.pdf" rel="nofollow">https://web.stanford.edu/group/scpnt/gpslab/pubs/papers/Liu_...</a>I have some other ideas about how to do that localization.<a href="https://twitter.com/lemonodor/status/1764054377982308484" rel="nofollow">https://twitter.com/lemonodor/status/1764054377982308484</a>"Do aircraft systems really only use GPS and not the full
constellation of navigational satellite systems?"ADS-B doesn't tell you what navigation system is, but my understanding
is that most aircraft are still using GPS. Maybe someone who works on
aircraft avionics will chime in. A few years ago I did see data that
distinguished between different GNSS, and GPS was experiencing more
jamming than the others. I assume as multi-network systems become more
and more common jammers will just target all of them, if they're not
already."There looks like a big hole of no data over Ukraine, where I'd most
expect GPS jamming, but I suppose there are no civilian flights
either. Maybe they could setup an GPS observation station on the
ground at a surveyed point to get data there."That's right, no (or few) flights over Ukraine with ADS-B transponders
means no data. I actually first started mapping GPS jamming on
Feb. 14, 2022
(<a href="https://gpsjam.org/?lat=45.00000&lon=35.00000&z=3.0&date=2022-02-14" rel="nofollow">https://gpsjam.org/?lat=45.00000&lon=35.00000&z=3.0&date=202...</a>),
because I thought it might give me an early warning of the expected
Russian invasion of Ukraine. It didn't work out that way--there was no
indication of interference right up until Feb 24., and then all civil
aviation stopped and there was no more data for that region
(<a href="https://gpsjam.org/?lat=49.18928&lon=33.51687&z=3.9&date=2022-02-24" rel="nofollow">https://gpsjam.org/?lat=49.18928&lon=33.51687&z=3.9&date=202...</a>).As some of you have noticed, GPS jamming is highly correlated with
conflict zones. Some conflicts are higher intensity than others--for
example, I think the airspace around Cyprus has been jammed for years
(since 2018 maybe?), and I get the feeling it's more harrassment than
anything else (maybe someone more geopolitically savvy than me knows
more)."I see 2 red cells on the US/Mexico border right about Texas/Coahuila
region". Someone always says it's cartels, and the evidence is that
it's much more likely to be U.S. military testing and training. First,
the interference is always in the Laughlin and Randolph military
operating areas (MOAs) (<a href="https://imgur.com/vieGhgN" rel="nofollow">https://imgur.com/vieGhgN</a>). Second, the
interference usually runs during the week and takes weekends
off--which I doubt cartels do, but that's the typical pattern seen for
military exercises."am I missing any other GPS jamming mapping or data collection projects?"From 2/24/2022 until 3/19/2024, gpsjam.org was the only site with
regularly updated GPS jamming maps. On Twitter, @auonsson
(<a href="https://twitter.com/auonsson" rel="nofollow">https://twitter.com/auonsson</a>) and @rundradion
(<a href="https://twitter.com/rundradion" rel="nofollow">https://twitter.com/rundradion</a>) have been posting geospatial and
other analysis of similar data for the past several months at least,
and @x00live (<a href="https://twitter.com/x00live" rel="nofollow">https://twitter.com/x00live</a>) has looked at ADS-B and GPS
interference for a while too. (I'm not even going to try to catalog
academic or government efforts, though I will mention HawkEye 360's
satellite based GPS interference mapping:
<a href="https://spacenews.com/hawkeye-360-gps-ukr/" rel="nofollow">https://spacenews.com/hawkeye-360-gps-ukr/</a>)"If line of sight to the jamming antenna is required to be jammed, why
do aircraft not have a downwards shield so that they only receive GPS
signal from the sky (satellites) and not from jammers (coming from the
bottom hemisphere)? Or is the jamming signal so many orders of
magnitudes stronger than the satellites that there's always going to
be some gain no matter how good the shield is?"Yes, GPS signals are so weak (below the noise floor!) that it's just
super easy to overpower them with terrestrial (or airborne)
jammers. But there are special antennas and other techniques for
building jam-resistant systems, e.g. "controlled reception pattern
antennas" (CRPA):
<a href="https://www.gpsworld.com/anti-jam-technology-demystifying-the-crpa/" rel="nofollow">https://www.gpsworld.com/anti-jam-technology-demystifying-th...</a>
But I think the main reason most civilian aircraft systems aren't jam
resistant is because they didn't need to be--For the past several
decades GPS jamming has been a much smaller issue than it is now, and
I don't think there was sufficient reason to spend time and money on
what would have been an over-engineered, mostly unnecessary
system. But the situation is changing, and I expect anti-jamming to
become a more significant concern by equipment manufacturers and
aviation authorities.[Edited to add:]"I'm in the middle of one of the red blobs on the map and just used my
phone with google maps to drive around. It worked fine."From the GPSJAM FAQ: ""I live in one of the red zones and my GPS was
fine?""
(<a href="https://gpsjam.org/faq/#i-live-in-one-of-the-red-zones" rel="nofollow">https://gpsjam.org/faq/#i-live-in-one-of-the-red-zones</a>). Yeah, the
answer is, as you mentioned, aircraft fly at higher altitudes, so they
get much longer line of sight to the jammer.On the general idea of using ADS-B to map GPS interference, when I
thought of this idea I was pretty excited. I realized that if you had
access to worldwide ADS-B data, which ADS-B Exchange graciously gave
me as part of my Advisory Circular project
(<a href="https://news.ycombinator.com/item?id=24188661">https://news.ycombinator.com/item?id=24188661</a>), you could also make a
worldwide map of GPS jamming, and I hadn't seen anyone do that before
(later I found some researchers who realized you could get GPS jamming
information from ADS-B, but they only looked at a couple
aircraft).I just think it's pretty neat that even though there were multiple
companies devoted to processing, analyzing, and selling ADS-B data,
and ADS-B data is not all that complicated, none of those companies
had realized this new way of using it. Sometimes there's gold left
even in data that you think must have been completely mined out.Even specifically looking at ADS-B data as it relates to GPS
interference, there's still lots to be done! FR24 is mapping jamming,
but I don't think anyone else has made worldwide maps of spoofing
(yet!): <a href="https://twitter.com/lemonodor/status/1770515361739493488" rel="nofollow">https://twitter.com/lemonodor/status/1770515361739493488</a>[Edited to add more:]With respect to safety issues, yes, aircraft have redundant navigation
systems. But GPS is one of the important layers that add safety to
aviation, and it is not at all normal for entire countries or even
larger regions to lsoe GPS while still maintaining passenger
flights. This Eurocontrol presentation, "GNSS Interference and Civil
Aviation", has lots of details:
<a href="https://rntfnd.org/wp-content/uploads/Aviation-GNSS-interference-UN-ICG-WGS-IDM-ECTL-GNSS-RFI-SEP23.pdf" rel="nofollow">https://rntfnd.org/wp-content/uploads/Aviation-GNSS-interfer...</a>From the presentation:<pre><code> Aviation Safety is built on two main principles:
• Trust your instruments
• Follow standard operating procedure
GNSS RFI causes pilots to have to question both principles!
</code></pre>
There have been close calls due to lack of GPS. It increases workload
for both pilots and controllers, which is a safety issue by
itself. Despite a lot of airlines and government aviation agencies
saying everything is fine, they're not really prepared for a world
with frequent GPS denial, and everything is not fine. Industry and
government are organizing emergency meetings about how to handle this
in a less ad hoc way than they have been so far (commercial aviation
is kind of the opposite of ad hoc).

jjwiseman: I-；我已经使用ADS-B数据绘制GPS干扰图好几年了年和I-；I’我试着回答这里提出的问题和要点根据我所知 HN:2022:<a href=“https://；&#x2F；news.ycombinator.com&#x2F？id=32245346”>https:&#x2F&#x2F；news.ycombinator.com&#x2F；项目id=32245346</a>2023:<a href=“https://；&#x2F；news.ycombinator.com&#x2F？item？id=37868106”>https://&#x2F；news.ycombinator.com&#x2F；项目id＝37868106</a>（根据我对2023年那篇帖子的评论：“Why haven”t FlightRadar24，FlightAware，还是其他任何一个飞行跟踪器做到了这一点&quot；） ”；单个观察者可以；我真的不能肯定干扰是发生您需要来自多个不同的分布式样本传感器在一段时间内具有相当高的置信度&quot 你可以使用一些启发法，让你做出一个非常好的根据来自一架或两架飞机，过去在GPSJAM上运行良好几年 关于GPS干扰机的定位，是的，你可以做方向直接找到所发射的信号；s简单模式。对于有趣的挑战，仅基于对ADS-B数据的观测受影响的（和未受影响的飞机）。这里；s一种方法来自斯坦福大学GPS实验室的研究人员；GNSS干扰使用ADS-B数据的源定位”：<a href=“https:&#x2F；&x2F；web.stanford.edu&#xx2F；group&#x2F：scpnt&#x2F，gpslab&#x2F！pubs&#x2F；papers&#x2F&Liu_ION_ITM_2022_ADSB.pdf”rel=“nofollow”>https:&#x20F&#x2F；web.stanford.edu；组；scpnt；gpslab；pubs&#x2F；纸张；刘</a> 关于如何进行本地化，我还有一些其他想法 <a href=“https://；&#x2F；twitter.com&#x2F：柠檬味&#x2F，status&#x2F！1764054377982308484”rel=“nofollow”>https://&#x2F；twitter；柠檬味；status；1764054377982308484</a>“；飞机系统真的只使用GPS而不使用完整的GPS吗导航卫星系统的星座&quot ADS-B不；我不能告诉你什么是导航系统，但我的理解是大多数飞机仍在使用全球定位系统。也许有人在飞机的航空电子设备将会出现。几年前，我确实看到了数据区别于不同的全球导航卫星系统，而全球定位系统正在经历更多干扰比其他的。我认为随着多网络系统变得越来越多并且更常见的干扰器将仅针对所有干扰器；re不是已经p> ”；乌克兰上空似乎有一个没有数据的大洞；d最多预计GPS会受到干扰，但我想没有民用航班任何一个也许他们可以在在测量点进行地面测量，以在那里获取数据&quot 那个；是的，乌克兰上空没有（或很少）使用ADS-B转发器的航班意味着没有数据。事实上，我第一次开始绘制GPS干扰图2022年2月14日（<a href=“https://；&#x2F；gpsjam.org/x2F；？lat=45000000&amp；lon=300000&amp；z=3.0&amp；date=2022-02-14”rel=“nofollow”>https://；&x2F；gpsjam.org.&#x2F？lat=4500000&amp；lon=35000000&aamp；z=30.0&amp；date=202…</a>），因为我认为这可能会给我一个预期的预警俄罗斯入侵乌克兰。它没有；我不会那样做的——没有直到2月24日都有干扰的迹象，然后都是民事的航空停飞，没有更多该地区的数据（<a href=“https://；&#x2F；gpsjam.org/x2F；？lat=49.18928&amp；lon=33.5168&amp；z=3.9&amp；date=2022-02-24”rel=“nofollow”>https://；&x2F；gpsjam.org/x2F；？lat=49.18928&amp；lon=33.51687&amp；z=3.9&aamp；date=202…</a>） 正如你们中的一些人所注意到的，GPS干扰与冲突地区。有些冲突比其他冲突更激烈——因为例如，我认为塞浦路斯周围的空域已经堵塞多年了（也许从2018年开始？），我有一种感觉；It’比其他任何事情（也许是比我更懂地缘政治的人更多p> ”；我在US；墨西哥边境附近的得克萨斯州；科阿韦拉区域”；。总有人说；有证据表明它；这更有可能是美国的军事测试和训练。第一干扰总是发生在劳克林和伦道夫的军队中操作区域（MOAs）（<a href=“https://；&#x2F；imgur.com&#x2F！vieGhgN”rel=“nofollow”>https://。第二干扰通常在一周内发生，周末发生关闭——我怀疑卡特尔会这样做，但这；这是典型的模式军事演习 ”；我是否错过了其他GPS干扰测绘或数据收集项目&quot 从2/F；24；2022直到3；19；2024年，gpsjam.org是唯一一个拥有定期更新GPS干扰地图。在推特上，@aunsson（<a href=“https://；&#x2F；twitter.com&#x2F！auonsson”rel=“nofollow”>https://；&x2F；twitter.com/x2F；auonsson</a>）和@rundrain（<a href=“https://；&#x2F；twitter.com&#x2F！rundradin”rel=“nofollow”>https://；#xx2F；twitter.com/x2F；rundradin</a>）一直在发布地理空间和至少过去几个月的类似数据的其他分析，@x00live（<a href=“https://；&#x2F；twitter.com#xx2F；x00live”rel=“nofollow”>https://；&x2F；twitter.com&#x2F！x00live</a>）已经研究了ADS-B和GPS干扰也会持续一段时间。（我甚至不打算尝试编目学术或政府的努力，尽管我将提到HawkEye 360；s基于卫星的GPS干扰测绘：<a href=“https://；#x2F；spacenews.com&#x2F；hawkeye-360-gps-ukr&#x2F”rel=“nofollow”>https://&#x2F；spacenews.com&#x2F；hawkeye-360-gps-ukr</a> ）“；如果干扰天线的视线需要被干扰，为什么飞机没有向下的防护罩，所以只能接收GPS吗来自天空（卫星）而非干扰机的信号（来自下半球）？还是干扰信号太多了

gregmac: It's kind of neat how this works:> As part of the ADS-B messages we receive from each aircraft, the Navigation integrity category (NIC) encodes the quality and consistency of navigational data received by the aircraft. The NIC value informs how certain the aircraft is of its position by providing a radius of uncertainty.> Poor NIC values alone might indicate a problem with an aircraft’s equipment or unfavorable positioning. However, when observed in multiple aircraft in close proximity during the same time frame, it suggests the presence of a radio signal interfering with normal GNSS operation.A single observer can't really say for certain that jamming is happening; you need a distributed sample from multiple different sensors over a period of time to have reasonably high confidence.

gregmac: 它；这有点巧妙：&gt；作为我们从每架飞机接收的ADS-B消息的一部分，导航完整性类别（NIC）对飞机接收的导航数据的质量和一致性进行编码。NIC值通过提供不确定性半径来告知飞机对其位置的确定程度 &gt；NIC值差本身就可能表明飞机设备有问题或定位不利。然而，当在同一时间段内近距离观察到多架飞机时，这表明存在干扰全球导航卫星系统正常运行的无线电信号 单个观察者可以；我不能确定干扰正在发生；您需要一段时间内来自多个不同传感器的分布式样本才能具有相当高的置信度。

tivert: So how should I interpret this? The map lacks geopolitical boundaries, so it's hard to interpret.There looks like a big hole of no data over Ukraine, where I'd most expect GPS jamming, but I suppose there are no civilian flights either. Maybe they could setup an GPS observation station on the ground at a surveyed point to get data there.There's a big red blob over Turkey, is that maybe the southern edge of the reach of Russian jammers in the Black sea?There's also a big red blob over the eastern Mediterranean. Is that Israel? I'm not so sure though, because it's not centered on Israel and parts of Israel proper are green on the map. I also assume they're heavy users of GPS, so wouldn't want to jam it.There's a red blob in Southeast Asia, and that looks like Myanmar, where there's a civil war right now.There's a little red blob over what looks like Kashmir.

tivert: 那么我该如何解释呢？该地图缺乏地缘政治边界，因此；It’很难理解 乌克兰上空似乎有一个没有数据的大洞；我最期待的是GPS干扰，但我想也没有民用航班。也许他们可以在被测点的地面上建立一个GPS观测站，在那里获取数据 有；土耳其上空有一个巨大的红色斑点，那可能是俄罗斯干扰机在黑海的南部边缘吗 有；这也是地中海东部上空的一个大红色斑点。那是以色列吗？I-；我不太确定，因为；它不是以以色列为中心的，以色列部分地区在地图上是绿色的。我还假设它们；re是GPS的重度用户；我不想把它卡住；这是东南亚的一个红色斑点，看起来像缅甸，那里有；现在是一场内战 有；看起来像克什米尔的地方有一个红色的小斑点。

dfworks: If anyone found the above interesting, I wrote a short article mapping plane activity on FlightRadar's 'blocked' list (i.e FlightRadar had agreed to remove the ADBS data from their dataset following probable legal pressure).<a href="https://dfworks.xyz/blog/hnwi-osint-private-jet/" rel="nofollow">https://dfworks.xyz/blog/hnwi-osint-private-jet/</a>Slightly tangential so feel free to remove if irrelevant

dfworks: 如果有人觉得上面很有趣，我在FlightRadar上写了一篇关于飞机活动地图的短文；s-；blocked-7；列表（即FlightRadar已同意在可能的法律压力下从其数据集中删除ADBS数据） <a href=“https://；&#x2F；dfworks.xyz&#x2F！blog&#x2F：hnwi-osint私人飞机&#x2F”rel=“nofollow”>https://&#x2F；dfworks.xyz；博客&#x2F；hnwi osint私人飞机</a> 略微相切，因此如果不相关，请随意删除

toomuchtodo: <a href="https://www.flightradar24.com/data/gps-jamming" rel="nofollow">https://www.flightradar24.com/data/gps-jamming</a>Also: <a href="https://gpsjam.org/" rel="nofollow">https://gpsjam.org/</a> | <a href="https://hn.algolia.com/?q=gpsjam" rel="nofollow">https://hn.algolia.com/?q=gpsjam</a>(am I missing any other GPS jamming mapping or data collection projects?)

toomuchtodo: <a href=“https:#x2F；&#x2F；www.flightradar24.com.#x3F；data&#x2F：gps干扰”rel=“nofollow”>https:&#x2F&#x2F；www.flightradar24；数据；gps干扰</a>此外：<a href=“https://x2F；&#x2F；gpsjam.org&#x2F”rel=“nofollow”>https://x2F&#x2F；gpsjam.org&#x2F</a> |<a href=“https://；&#x2F；hn.algolia.com&#x2F？q=gpsjam”rel=“nofollow”>https://&#x2F；hn.algolia.com&#x2F；？q=gpsjam</a>（我是否缺少任何其他GPS干扰测绘或数据收集项目？）

JohnMakin: I went to school at a relatively late age and started in community college. The school/state had a policy where any independent income earners making less than 35,000/year would not pay tuition. A single dollar over that would require paying full tuition of ~$60/unit or about $750 a semester. One year I worked a little more overtime during the holidays than usual and realized with a week to go in the year that I'd go a few hundred dollars over, so I called out of a few shifts and nearly got fired over it. I barely squeaked in under the limit, and if I hadn't, there was pretty much no way I would have been able to continue school. It's not like I could suddenly afford it now that I made $35,001 vs $34,999. I have never understood why things like this don't use some sort of sliding scale, rather than absolute dividing line.

JohnMakin: 我上学的年龄相对较晚，开始在社区大学学习。学校&#x2F；该州有一项政策，任何收入低于35000；一年不付学费。超过一美元将需要支付约60美元的全额学费；单位或大约750美元一学期。有一年，我在假期里比平时加班多了一点，并意识到一年中还有一周的时间；我多花了几百美元，所以我叫了几个班，差点被解雇；t、我根本不可能继续上学。它；it’我现在挣了35001美元，而不是34999美元。我一直不明白为什么这样的事情；不要使用某种滑动标尺，而不是绝对的分界线。

nominatronic: A similar fun example is the distribution of Elo ratings on a chess site, e.g. here's the weekly distribution on Lichess for Bullet games (less than 3 minutes):<a href="https://lichess.org/stat/rating/distribution/bullet" rel="nofollow">https://lichess.org/stat/rating/distribution/bullet</a>It's easy to understand why this happens:- Player ratings will fluctuate by small amounts as they win and lose individual games.- People are happy to stop playing when their rating is at e.g. 1503, but if it's 1497, they'd rather play just one more game than leave it that way.- At any given time, most accounts are not playing, so the distribution shows a bias towards values just over a 100 Elo threshold.The other neat thing is that you can see this effect reduce as you look at longer time controls:Blitz (less than 10 min): <a href="https://lichess.org/stat/rating/distribution/blitz" rel="nofollow">https://lichess.org/stat/rating/distribution/blitz</a>Rapid (less than 30 min): <a href="https://lichess.org/stat/rating/distribution/rapid" rel="nofollow">https://lichess.org/stat/rating/distribution/rapid</a>Which makes sense because the time and effort of gambling just one more game to get the rating back over the line is higher at the longer time controls.

nominatronic: 类似的有趣示例是国际象棋网站上的Elo评级的分布；s子弹头巫妖游戏的每周分发（少于3分钟）&#x2F；liches.org&#x2F；stat；评级；分布；bullet</a>It；很容易理解为什么会发生这种情况：-玩家的评分会随着个人游戏的输赢而小幅波动 -当他们的评分为例如1503时，人们很乐意停止玩游戏，但如果是；s 1497；I’我宁愿多打一场比赛，也不愿就此打退堂鼓 -在任何给定的时间，大多数账户都没有玩，因此分布显示出对略高于100 Elo阈值的值的偏见 另一件巧妙的事情是，当你观察更长的时间控制时，你可以看到这种效果减少：闪电战（不到10分钟）：<a href=“https://；&#x2F；lichess.org&#x2F！stat&#x2F，rating&#x2F：distribution&#x2F”Blitz“rel=”nofollow“>https://&#x2F；liches.org&#x2F；stat；评级；分布；blitz</a>Rapid（不到30分钟）：<a href=“https://；&#x2F；lichess.org/&#x2F！stat&#x2F：rating&#x2F；distribution&#x2F，Rapid”rel=“nofollow”>https://&#x2F；liches.org&#x2F；stat；评级；分布；快速</a>这是有道理的，因为在控制时间越长的情况下，只需再赌一场游戏就可以将评分恢复到底线的时间和精力越高。

chubbyFIREthrwy: >One reason people were looking for ways to lose money was that, in the U.S., there's a hard income cutoff for a health insurance subsidy at $48,560 for individuals (higher for larger households; $100,400 for a family of four). ... That means if an individual buying ACA insurance was going to earn $55k, they'd be better off reducing their income by $6440 and getting under the $48,560 subsidy ceiling than they are earning $55k.I had the opposite problem for the 2022 tax year: I turned out that, with investment losses and no earned income, my adjusted income was below the poverty line, which ... means your ACA healthcare subsidy is cut off entirely!<a href="https://www.irs.gov/affordable-care-act/individuals-and-families/eligibility-for-the-premium-tax-credit" rel="nofollow">https://www.irs.gov/affordable-care-act/individuals-and-fami...</a>The "logic" there (from reading discussions of the cutoff) is that, "well, if you're below the poverty line, you should be on Medicaid and not on the ACA exchanges at all, silly!" Okay, but if you have wildly varying income, and a high income from previous years, you don't know that you'll be "in poverty" this year, and won't qualify because of the past year.I was tempted to update my taxes to claim phantom income from my imaginary cash-based business, which would then get me the subsidy, but that feels ick.(Which, I know, being retired on crypto, I also feel ick about taking the subsidies to begin with, but that's a different issue.)

chubbyFIREthrwy: &gt；人们寻找赔钱方式的一个原因是，在美国；这是个人48560美元的医疗保险补贴的硬性收入上限（大家庭更高；四口之家100400美元）。。。这意味着，如果购买ACA保险的个人将获得5.5万美元的收入；他们的收入减少6440美元，并低于48560美元的补贴上限，这比他们的收入5.5万美元要好 我在2022纳税年度遇到了相反的问题：我发现，由于投资损失，没有收入，我的调整后收入低于贫困线，这。。。意味着您的ACA医疗补贴被完全取消 <a href=“https:&#x2F；&x2F；www.irs.gov&#x2F，平价医疗法案&#x2F个人和家庭&#x2F保费税收抵免资格”rel=“nofollow”>https:&#x20F&#x2F；www.irs.gov&#x2F；平价医疗法案；个人和家庭</a> “；逻辑“；（从阅读关于截止的讨论中）是这样的：；好吧，如果你；在贫困线以下，你应该参加医疗补助，而不是ACA交易所，愚蠢&quot；好吧，但如果你的收入差异很大，而且前几年的收入很高，你就不会；我不知道你；将是“；贫困”；今年；由于过去的一年，我没有资格参赛 我很想更新我的税收，从我想象中的现金业务中申请虚幻的收入，这将为我提供补贴，但这感觉很恶心 （我知道，在加密货币上退休后，我也对一开始就接受补贴感到恶心，但这是另一个问题。）

armchairhacker: At least in the government, there should be a law that any hypothetical scenario where someone making more money before government taxes/incentives would cause them to earn less after, must be quickly resolved by replacing hard cutoffs with gradients.No benefits should apply 100% for anyone making under a certain amount and 0% for anyone making over. Instead there should be a range they slowly decrease, so that if you make $1 more before the benefit you still get less than $1 after. Maybe even a lot less, like only $.30. But you should never lose money.This is obvious. It goes to show how bad beaurocracy and subtle misaligned incentives are that these hard cutoffs ever existed in the first place.

armchairhacker: 至少在政府中，应该有一项法律规定，任何假设的情况下，有人在政府税前赚更多的钱；激励措施会导致他们的收入减少，必须通过用梯度取代硬边界来迅速解决 收入低于一定数额的人不应享受100%的福利，收入超过一定数额的则不应享受0%的福利。相反，应该有一个他们慢慢减少的范围，这样，如果你在福利之前多赚了1美元，那么在福利之后你仍然赚不到1美元。也许更少，比如只有.30美元。但你永远不应该亏本 这是显而易见的。这表明，这些硬边界从一开始就存在，美丽和微妙的错位激励是多么糟糕。

mrandish: Coding hard cut-offs like this into legislation, regulation or policies seems crazy almost to the point of negligence, incompetence or malice. Especially when it's so obvious such cliffs will incentivize behavior certain to cause negative or perverse outcomes. It's even more incomprehensible when implementing graduated thresholds is so well understood.A related common failure mode is baking in fixed, absolute thresholds for dynamic domains sure to evolve instead of linking thresholds to dynamic metrics (such as inflation, cost of living, etc).

mrandish: 将这样的硬性规定写入立法、法规或政策似乎有些疯狂，几乎到了疏忽、无能或恶意的地步。特别是当它；很明显，这样的悬崖会激励某些行为，从而导致负面或反常的结果。它；当人们对分级阈值的实现如此了解时，这就更令人费解了 一种相关的常见故障模式是为一定会发展的动态领域设置固定的绝对阈值，而不是将阈值与动态指标（如通货膨胀、生活成本等）联系起来。