Finally finishing yesterday's post!

WEDNESDAY, DECEMBER 9, 2020

South Dakota compared to New York state: Doggone it! We forgot to finish yesterday's post about the problem with the Covid statistic known as "positivity rate."

As we noted, Robin Lloyd has offered a critique of the funky statistic at New York magazine. Her essay appeared beneath a straightforward headline:

       "The Problem With the Positivity Rate."

That's what the headline said. To our ear, Lloyd seemed to be doing a decent job until she came up with this:

LLOYD (12/7/20): [M]ost researchers avoid relying on any single number such as the positivity rate to understand the status of a community’s outbreak, preferring to examine it alongside other statistics, such as the number of and trend direction for positive coronavirus cases in a community...

For instance, it would be misleading to base policy on South Dakota’s 448 new infections reported on December 1 without also looking at its eye-popping positivity rate of 42.5 percent. Together, these numbers start to paint a picture of a runaway outbreak and insufficient testing. By contrast, New York state on the same day reported over 16 times more new infections (7,413). In the context of the state’s 3.7 percent positivity rate that day, it could suggest a more controlled outbreak and enough testing to inform efforts to control or respond to transmission. 

We thought that passage was very strange—but we also thought it teaches us an anthropology lesson. First, though, what's the general problem with the use of the "positivity rate?" And what the heck is it, anyway?

When you record a state's positivity rate, you're recording what percentage of Covid tests come back positive. But that, of course, may be affected by the number of people being tested and by who those people are.

Imagine this:

State A is testing a wide cross-section of its population. By way of contrast, State B is only testing people who arrive at an emergency room displaying very bad symptoms.

All things being equal, State B will record a much higher "positivity rate." That said, there's little to gain from  a comparison between two states with such different testing regimens.

We thought Lloyd was doing a decent job explaining that point—but then, she presented that passage. Immediately, the analysts began to scream and cry. They pointed to some obvious problems:

How weird! Lloyd said that, on a certain day, New York state recorded 16 times more new infections (new cases) than South Dakota did. She didn't mention a basic fact:

New York state's population is roughly 22 times the size of South Dakota's.

Under the circumstances, it seemed strange to mention the one fact without mentioning the other. Meanwhile, Lloyd had cited the numbers from one particular day, rather than looking at the average numbers of new cases over the course of a given week.

Was New York's number of new cases 16 times the size of South Dakota's on that one particular day? Lloyd didn't say where her numbers came from, but yes, it basically was, according to New York Times numbers. 

But over the course of the 7-day week which ended on December 6, the number of New York state's new cases was only 10.6 times as large as South Dakota's. It seemed weird to juxtapose numbers from those two states based upon one single day, and without making any attempt to cite the large difference between the two states' populations.

Whatever Lloyd was trying to do in that passage, it seemed to us that none of its made any obvious sense. This is why we say that:

President Trump's lunatic rantings on the topic to the side, the number of new cases a jurisdiction records will depend, in part, on the amount of testing that jurisdiction is conducting, and also on who's getting tested.  Consider what Lloyd says about those numbers from South Dakota:

Is a 42.5% positivity rate really a sign of a "runaway outbreak?" Not necessarily, no. What if you're only testing people when they show up at the hospital with apparent symptoms? 

In that case, wouldn't you expect to record a high positivity rate? The positivity rate, by itself, wouldn't necessarily mean that you had a large outbreak.

How about South Dakota's 448 new infections that day? Would a number like that, day after day, indicate a "runaway outbreak?"

Not necessarily, no. In the case of South Dakota, it might, due to the state's small population. In a much larger jurisdiction, that number of new infections would look very different.

In short, Lloyd's analyses didn't seem to make much sense. We were especially struck by the comparison in the number of new cases, without any mention of the fact that New York State has a much larger population than South Dakota. But no part of her presentations seemed to us to make any real sense.

Alas! Within the world of mainstream journalism, Covid statistics are still very hard. The worst part of the story is this:

By now, we're nine months in!

The most direct comparison: The number of Covid cases will be affected by the amount of testing. Almost surely, the number of Covid deaths, while imperfect, is a more reliable measure.

Lloyd wasn't exactly trying to compare the outbreaks in those two states. But just for the record, here are the two states' current numbers for Covid deaths, based on Financial Times numbers:

Covid deaths per day, per million population, as of December 7 (7-day averages):
South Dakota: 26.3
United States, nationwide: 6.4
New York state: 3.6

Which state has the larger outbreak? Using Covid deaths, and adjusting for population, it seems fairly easy to tell.

Presumably, "Covid deaths" remains a more reliable measure than "Covid cases." But none of these numbers means a darn thing if you don't take the size of population into account. 

Covid statistics remain very hard. According to experts, this is an anthropological fact about our upper-end press corps and about the jumbled state of our national discourse.


17 comments:

  1. Bob, nobody cares about any of this. Americans never expected their government to be prepared for a virus or to be competent in response to any emergency. We're not Japan, Taiwan, South Korea, New Zealand, Australia, Canada, or Norway, where people demand competence. We don't believe in the possibility of competent group action or progress like those Commie societies. We're rugged individualists who believe bad things are a punishment from an angry God that we worship with cult-like devotion. It's obvious that you don't get out much and that you’ve never met the residents of "Their Town."

    ReplyDelete
    Replies
    1. I want to thank Emu Temple for the accurate readings he gave me and for also helping me bring back my lover.. If you are here and you are having any relationship problem please Contact Emu Temple on Via Email: emutemple@gmail.com OR Via WhatsApp +2347012841542 and result is 100% guarantee and He do lot more as:*Love Spells*Lost Love Spells*Divorce Spells*Stop Divorce Spell*Marriage Spells*Binding Spells*Breakup Spells*You want to be promoted in your office*Want to satisfy your lover*Death Spell*Gay/Lesbian Love Spell*Court case Spell*Politics Spell*Good-luck Spell*Bad Luck Remover Spell*Do as i say Spell*General cleansing Spell*Herbal remedy for all kind of disease    
      *Lottery Spell*Pregnancy Spell*Peins enlargement 

      Delete
    2. Thank you Thank You Very much Doctor Otonokpo for making my ex boyfriend come back to me. I am Cordelia Sandra from Brazil and i am putting this testimony here too because i want to share my testimony of how i was helped by Doctor Otonokpo within 48 hours of contacting him. Yes, it was last week my ex boyfriend returned to me after i contacted Doctor Otonokpo. My boyfriend was always going back to meet his ex girlfriend because he never really left her. Her name was Sophie. I didn't know how it happened one day after breakfast that i saw him looking at his ex girlfriend's picture on Facebook and I flared at him that he doesn't care about him and he was with me and still thinking about his ex although we have been dating for 6 months. He stormed at me and left the house and never returned. I was heartbroken and wanted him to come back. I was in a nightclub with friend one evening that I saw him with Sophie there, I was humiliated that night and I regretted going there only to see him there. I went online after some days and found Doctor Otonokpo and read about him and I contacted him to help me get him back. I must say that within 48 hours, my boyfriend came back to me and pleaded for leaving me. Is this how spell works so fast? Please, if you want help, contact Doctor Otonokpo too to help you at otonokpotemple@gmail.com
      Call/WhatsApp +2348114129781

      Delete
  2. "Is a 42.5% positivity rate really a sign of a "runaway outbreak?" Not necessarily, no."

    This is why Lloyd uses words like "could" and "might" when talking about what the numbers represent. She has properly qualified her statements. Somerby wishes to use the fact that there might be circumstances that would make that 42% not represent a runaway outbreak as a reason to say that Lloyd should not suggest that possibility. Even when, given the circumstances in South Dakota, it is most likely that their numbers do indicates such a runaway outbreak.

    As was pointed out yesterday, Lloyd is saying that multiple indicators are needed to fully understand what is going on. Somerby is saying that there need to be more than two such measures, but also info about who is being tested. Lloyd would not disagree with that. So what is Somerby's beef?

    You can invent an explanation to account for any set of data that would be contrary to what is actually true, if you allow yourself enough imagination. There is an additional test of what is most likely given the patterns found in the data. Somerby raises his complaint about certainty again -- the existence of highly unlikely, even specious alternatives does not mean that you shouldn't draw conclusions based on broader contextual knowledge and what is most likely to be true given the statistics at hand.

    Somerby may understand how to calculate a rolling average or a death rate, but he doesn't understand how to reason about statistics, how to interpret data, how to use data to inform policy decisions and planning.

    Because Somerby is ignorant and also doesn't know how ignortant he is, he daily says stupid things as criticisms of people who are offering better information than he is giving them credit for. That is annoying, if not harmful, much like Trump and the Fox hosts he has become so fond of watching. And it isn't any better when he talks about NAEP scores or integration of school districts.

    ReplyDelete
  3. This comment has been removed by the author.

    ReplyDelete
  4. Somerby’s idiocy, whether willful or not, is on full display here.

    It almost seems he is trying to explain why the positivity rate is problematical in order to criticize Lloyd, only for the TDH reader to discover that he is merely repeating what Lloyd has written.

    But his one actual criticism falls completely apart. He thinks that Lloyd is being stupid by failing to note New York’s population vis-a-vis South Dakota’s as if that alone is a viable explanation for New York’s 7413 vs South Dakota’s 448 new infections. But in doing this, he completely fails to understand the argument Lloyd is making.

    If South Dakota has 448 new cases with a positivity rate of 42.5 percent, that means South Dakota performed 1054 tests. New York’s 7413 new cases with a positivity rate of 3.7 percent means New York performed 200,351 tests.

    That means New York performed 190 times more tests than South Dakota, and yet they only had 16.5 times the number of new cases.

    Lloyd’s attempt at explaining the positivity rate went right by Somerby apparently.

    ReplyDelete
  5. I'm going to assume Somerby knew how math worked at one time, but had to give up that knowledge in order to become a Conservative.

    ReplyDelete
  6. Am here to testify what this great spell caster done for me. i never believe in spell casting, until when i was was tempted to try it. i and my wife have been having a lot of problem living together, she will always not make me happy because she have fallen in love with another man outside our relationship, i tried my best to make sure that my wife leave this woman but the more i talk to her the more she makes me fell sad, so my marriage is now leading to divorce because she no longer gives me attention. so with all this pain and agony, i decided to contact this spell caster to see if things can work out between me and my wife again. this spell caster who was a man told me that my wife is really under a great spell that she have been charm by some magic, so he told me that he was going to make all things normal back. he did the spell on my wife and after 5 days my wife changed completely she even apologize with the way she treated me that she was not her self, i really thank this man his name is Dr Odion he have bring back my wife back to me i want you all to contact him who are having any problem related to marriage issue and relationship problem he will solve it for you. his email is wisdomspiritualtemple@gmail.com he is a man and his great. wish you good time.
    He cast spells for different purposes like
    (1) If you want your ex back.
    (2) if you always have bad dream
    (3) You want to be promoted in your office.
    (4) You want women/men to run after you.
    (5) If you want a child.
    (6) You want to be rich.
    (7) You want to tie your husband/wife to be yours forever.
    (8) If you need financial assistance.
    (9) HIV/AIDS CURE
    (10) is the only answer to that your problem of winning the lottery

    Contact him today on:wisdomspiritualtemple@gmail.com or whatsapp him on +2348136482342

    ReplyDelete
  7. I want to thank Emu Temple for the accurate readings he gave me and for also helping me bring back my lover.. If you are here and you are having any relationship problem please Contact Emu Temple on Via Email: emutemple@gmail.com OR Via WhatsApp +2347012841542 and result is 100% guarantee and He do lot more as:*Love Spells*Lost Love Spells*Divorce Spells*Stop Divorce Spell*Marriage Spells*Binding Spells*Breakup Spells*You want to be promoted in your office*Want to satisfy your lover*Death Spell*Gay/Lesbian Love Spell*Court case Spell*Politics Spell*Good-luck Spell*Bad Luck Remover Spell*Do as i say Spell*General cleansing Spell*Herbal remedy for all kind of disease    
    *Lottery Spell*Pregnancy Spell*Peins enlargement 

    ReplyDelete
  8. HERBAL DR EMU WHO PREPARE HERBAL MEDICINE TO CURE ALL KINDS OF DISEASES INCLUDING HERPES DISEASE.   
     I have been battling this Herpes disease for almost 3 years now....I tried all possible means to get cure from my Herpes Disease but all to be in vain until i saw a post in a health forum about a herbal Dr Emu who prepare herbal medicine to cure all kind of diseases including Herpes Disease, at first i doubted if it was real but decided to give it a try...when i contact Dr Emu via his email (emutemple@gmail.com)  write him and reply me explain how the process work so after ordering for the medicine I got it within 3/4 working days through DHL Delivery and I took it according to the way Dr Emu instructed, I was so happy after 2 week I took the medicine there was very big change in my health when I was done with the process I go for test, I found out I am negative...Herpes patients should also get in touch with this herbalist Dr Emu to get rid of these Herpes Virus forever his whatsapp number +2347012841542. Website: https://emutemple.wordpress.com/ 

    ReplyDelete
  9. This year 2020 has been so blissful to me for God has given me a reason to live happily again after been heart broken for 6 years when my husband neglected me and went back to he's mistress. I suffered and went through all types of emotional tortures for i couldn't get any help to get my man back not until i was refereed to Dr. Iyaya by my co-worker who gave me her full assurance about him that he can be of help to me. I got in touch with Dr. Iyaya and i hearken to his words and followed the instructions given to me by him. Could you believe that my husband got back home within 48hours as said by him and today, my marriage is restored & i'm so thankful, appreciative & grateful to God for using Dr. Iyaya to get my man back after 9 months of broken marriage. Is there anyone out there who needs to get back to he's or her lover back or needs any help of any kind? Then, i suggest that you get in touch with Dr. Iyaya now through his Email: doctoriyaya@gmail.com Call WhatsApp +2347032756397 for more information, visit his website you may found your solution there www.https://dr-iyaya-herbal-remedy.webnode.com God bless you sir.

    ReplyDelete
  10. My husband and I have been having lots of problems living together, he never gives me attention or makes me happy because he has fallen in love with another woman outside our marriage. I tried my best to make sure that my husband leaves this woman but the more I talk to him about it the more he makes me feel sad and unhappy, My marriage started leading to divorce because he no longer gives me attention. I wanted to forget him but i love him and didn't want to lose him. We have been married for years and he is all I could call a true best friend and best in all, the man that handles my problems perfectly, the man that makes sacrifices for ,my happiness. I wanted him back in my life badly and I was so confused. My Friends told me to buy books about relationships, so I went online for relationship books while I came across a spell caster called Dr Emu. I read testimonies and reviews about him so I contacted him immediately, explained my problems to him. Same day , he casted a spell for me and assured me for 2 days that my husband will return to me and to my greatest surprise the third day my husband came knocking on my door and begged for forgiveness. I am so happy that my love is back again and not only that, we are about to get married again, he proposed. I wouldn't stop talking about him. Contact him today if you need his help via email: emutemple@gmail.com and you will see that your problem will be solved without any delay. Website: https://emutemple.wordpress.com/

    ReplyDelete
  11. Thank you Thank You Very much Doctor Otonokpo for making my ex boyfriend come back to me. I am Cordelia Sandra from Brazil and i am putting this testimony here too because i want to share my testimony of how i was helped by Doctor Otonokpo within 48 hours of contacting him. Yes, it was last week my ex boyfriend returned to me after i contacted Doctor Otonokpo. My boyfriend was always going back to meet his ex girlfriend because he never really left her. Her name was Sophie. I didn't know how it happened one day after breakfast that i saw him looking at his ex girlfriend's picture on Facebook and I flared at him that he doesn't care about him and he was with me and still thinking about his ex although we have been dating for 6 months. He stormed at me and left the house and never returned. I was heartbroken and wanted him to come back. I was in a nightclub with friend one evening that I saw him with Sophie there, I was humiliated that night and I regretted going there only to see him there. I went online after some days and found Doctor Otonokpo and read about him and I contacted him to help me get him back. I must say that within 48 hours, my boyfriend came back to me and pleaded for leaving me. Is this how spell works so fast? Please, if you want help, contact Doctor Otonokpo too to help you at otonokpotemple@gmail.com
    Call/WhatsApp +2348114129781

    ReplyDelete
  12. Get solution to your problems today and forever
    I can't believe that this man is so real, how can I thank you enough, I can't fail to testify about the good things you have been doing for me and now you still went ahead and do same for my friend, please everyone if you have anything disturbing you please your solution is hear with Dr. Otonokpo the great spiritualist who can solve any problem in a twinkle of an eye. No matter the problems, whether spiritual problem, you want to get your ex back, promotion in your workplace, spiritual cleansing, fruit of the womb, mental illnesses, protection for gun, protection for cutlass, protection for bottle, protection for snake and scorpion bites and cure. Are you a victim of any of the above listed setbacks, you can contact Dr. Otonokpo via Email: otonokpotemple@gmail.com
    Call/WhatsApp +2348114129781

    ReplyDelete

  13. LOTTO, lottery,jackpot.
    Hello all my viewers, I am very happy for sharing this great testimonies,The best thing that has ever happened in my life is how I win the lottery euro million mega jackpot. I am a Woman who believe that one day I will win the lottery. finally my dreams came through when I email believelovespelltemple@gmail.com and tell him I need the lottery numbers. I have spend so much money on ticket just to make sure I win. But I never know that winning was so easy until the day I meant the spell caster online which so many people has talked about that he is very great in casting lottery spell, . so I decide to give it a try.I contacted this great Dr Believe and he did a spell and he gave me the winning lottery numbers. But believe me when the draws were out I was among winners. I win 30,000 million Dollar. Dr Believe truly you are the best, all thanks to you forever

    ReplyDelete
  14. Are you in bad need of love spell to bring back your ex lover or reunite your marriage? Email Dr Isikolo for fast 48 hours solution. My name is Maria Tomescu and I had a problem with my husband a year and six months ago, which lead us apart. When he broke up with me, I was confuse and did not know what to do to get him back, I felt so empty inside. Until i came across Dr Isikolo on the internet on how He has helped so many people solve there various problem. I emailed Him and I told Him my problem and i did what he asked me to do for him to help me, to briefly make the long story short, Before I knew it, in less than 48 HOURS, my Husband gave me a call and he came back to me and told me he was sorry about what was going on between the both of us. Finally I am writing this testimony to offer my thanks and deep gratitude to you Dr Isikolo for keeping to your words and your promises in bringing him back to me in just 48 hours of your powerful spell casting, and for using your gifted and great powers to bring him back. If you need his help, you can email him at: isikolosolutionhome@gmail.com You can also Whatsapp/Viber him on +2348133261196.

    ReplyDelete
  15. I was married at 32 and immediately tried to get pregnant. When I was unable to conceive I had blood tests for fertility and was told that I had an FSH (follicle stimulating hormone) of 54 and would not be able to have children. Even though the doctors knew that I had been diagnosed with Hashimoto’s thyroiditis since age 25, no one bothered to check my thyroid levels. my TSH was measured at .001. My Synthroid dosage was lowered. a friend advise me to contact a spiritualist who help with fertility with his medicine, i collected his contact and explain my situation to him he prepared for me a herbal medicine which i took as describe by him. became pregnant very quickly, I had a successful pregnancy. I have my baby august 2017. to get pregnant at age 35 with my 2nd child in september 2019, thank you sir , this is his email contact if you require his help babaka.wolf@gmail.com or Facebook at priest.babaka

    ReplyDelete