#predictor 2020

ESOQ...  Now According to Predictor 2020.

I’m so excited to do the Estimated Size of Quiver (ESOQ) with Predictor 2020...  Finally!  Y’all have been requesting an ESOQ Update a lot, but I’ve been putting it off, because I wanted to finish the New Predictor first.  Now, it’s done.  So, by request, here’s each couple’s ESOQ per Predictor 2020, as of March 13, 2020—

(Link to the Previous ESOQ Update, for those who want to compare.  Below, I’ll also note the shift in ESOQ, vs. the Previous ESOQ.  Note that Predictor 2020′s algorithm contains several significant changes / improvements, so any massive changes are likely attributable to those changes.  A Post explaining all of these changes and new features is forthcoming.)

The Duggars—

Josh + Anna   11 Children  (–1 Child vs. Previous ESOQ)

Jana   6 Children  (–1)

John + Abbie   7 Children  (–1)

Jill + Derick   8 Children  (–2)

Jessa + Ben   12 Children  (–1)

Jinger + Jeremy   7 Children  (–4)

Joe + Kendra   15 Children  (–4)

Josiah + Lauren   13 Children  (–3)

Joy + Austin   15 Children

Younger Males   10 Children Each  (–2)

Younger Females   12 Children Each  (–2)

Predictor 2020 expects Jim Bob + Michelle to have 202 Grandchildren, in the end.  As of March 14, 2020, 17 of 202 (or 8.4%) have already arrived.  Jim Bob + Michelle have 19 Children, so that’s an average of 10.6 Children Per Couple.

 The Bateses—

Zach + Whitney   10 Children  (No Change)

Michaela + Brandon   4 Children

Erin + Chad   15 Children  (+1)

Lawson   8 Children  (–3)

Nathan   9 Children  (–3)

Alyssa + John   15 Children  (–3)

Tori + Bobby   17 Children  (No Change)

Trace   11 Children  (–3)

Carlin + Evan   21 Children  (No Change...  Yikes.)

Josie + Kelton   20 Children  (–2)

Katie + Travis   15 Children

Younger Males   12 Children Each  (–2)

Younger Females   15 Children Each  (–4)

As for the Bateses...  Predictor 2020 expects Gil + Kelly Jo to ultimately have a very impressive 250 Grandchildren (!), of which 14 (5.6%) are born or in–utero.  With 19 Children in the Bates Family, that’s about 13.2 Children Per Couple.  

The Maxwells—

Nathan + Melanie   7 Children  (Quiver Complete!)

Chris + Anna Marie   10 Children

Sarah   0 Children

Joseph + Elissa   8 Children

John + Chelsy   9 Children

Anna Elizabeth   7 Children

Jesse   8 Children

Mary   9 Children

A more modest 58 Grandchildren is expected for Steve + Teri Maxwell.  Out of 58, 18 (31.0%) have already arrived or are in–utero.  The Maxwell Clan consists of 8 Children, so that’s a rate of 7.25 Children Per Couple, or 8.3 Children Per Couple, if we exclude Sarah.  (Note that 38 Year Old Sarah’s ESOQ is 0.  She’s actually not expected to court or marry, since she’s now so late to do so...  The New Predictor has a feature which decides, at a specified point (Overdue by 5+ SDs and 5+ Years), that ‘late’ events probably won’t ever occur.  Nifty!)

The Kellers—

Esther + John   14 Children

Priscilla + David   10 Children

Anna + Josh   11 Children

Nathan + Nurie   11 Children  (Assuming 7–3–20 Wedding)

For the Kellers, Duggar Data will track only the quiverfull couples—i.e., Esther + John, Priscilla + David, Anna + John, and Nathan + Nurie.  Given the number of his siblings who have left the quiverfull faith, I won’t assume that David Keller—the youngest Keller son—will be quiverfull.  Whenever Duggar Data talks about the Kellers, I’ll be talking only about the quiverfull couples...  So, the grandchild totals don’t include the children (born or yet to be born) for the others.

Anyway...  Mike + Suzette can expect 46 Grandchildren (from Quiverfull Sons / Daughters), per Predictor 2020.  As of March 2020, 23 of 46 (50%) have been born, or are in–utero.  With 4 Known Quiverfull Couples, the Kellers’ typical rate is 11.5 Children Per Couple.

The Bontragers—

Chelsey + John   9 Children

Mitchell + Bryn   6 Children

Allison   7 Children

Carson + Carolina   8 Children

Joshua + Cassidy   10 Children

Younger Males   10 Each

Younger Females   10 Each

Per Predictor 2020 on March 14, 2020, Marlin + Becky can expected a total of 90 Grandchildren, of which 6 (6.7%) are born (4) or in–utero (2).  This is a rate of 9 Children Per Couple, across the Bontragers’ 10 Children.

Miscellaneous—

Sierra + Mark   13 Children  (Duggar Adjacent)

Kristen + Justin   9 Children  (Duggar Adjacent)

Bethany + Dav   5 Children  (Girl Defined)

One of the best things about Predictor 2020 is it’s ability to very easily expand, adding new couples or families.  For one–off couples, their own, personal data is used whenever possible; when personal data isn’t available, predictions will be based on averages taken from all other Predictor Couples.

TL;DR—

According to Predictor 2020 on March 14, 2020, the 10 Most Prolific Couples will be—

#10—Sierra + Mark Dominguez   13 Children

#9—Esther (Keller) + John Shrader   14 Children

(Tie)—Erin (Bates) + Chad Paine   15 Children

(Tie)—Alyssa (Bates) + John Webster   15 Children

(Tie)—Joe + Kendra (Caldwell) Duggar   15 Children

(Tie)—Joy (Duggar) + Austin Forsyth   15 Children

(Tie)—Katie Bates + Travis Clark   15 Children

#3—Tori (Bates) + Bobby Smith   17 Children

#2—Josie (Bates) + Kelton Balka   20 Children

#1—Carlin (Bates) + Evan Stewart   21 Children

It’s New, Improved, and Better Than Ever  (Part 2)

The Predictor is Duggar Data’s favorite forecasting tool.  It’s a massive Excel workbook, written by yours truly, that tracks all of the data—i.e., dates—about relationships and pregnancies, crunches that data, and then plugs all of the data into an algorithm to predict future events.  Predictor 1.0 hit the scene almost 2 Years Ago...  Since then, I’ve improved it several times, but Predictor 2020 is by far the most significant revision.  Honestly, it’s a total rebuild, which incorporates more data than ever before, tweaks the algorithm to hopefully be more accurate and realistic, and allow for future expansion.  (Now, I can easily add new families, or make specific predictions for the 4th Generation!)

Here’s a quick overview of Predictor 2020—what’s the same, what’s different.  Part 1 focused on what’s the same.  Now, we’ll talk about what’s new.

What’s New + Improved—

Factoring in Miscarriage Data—

For the first time, Predictor 2020 incorporates data from known miscarriages or stillbirths.  I’ll admit that, in the past, I’ve been hesitant to add this feature.  But, after Joy + Austin lost Annabell, I decided it was critical not to ignore this data.

Miscarriages will impact Child Spacing, as follows—

Losses w/ Known Due Date + Loss Date   If the baby’s due date a date of loss are both known (e.g., Asa, Annabell), or if one is known and the other can be reasonably estimated (e.g., Erin’s 1st Miscarriage, Whitney’s 2018 Miscarriage, Melanie Maxwell’s 2009 Miscarriage), Duggar Data assigns a Child Spacing to the loss itself, representing how closely that child would have been spaced after the prior child, prior loss, or marriage.  Here’s the formula:  Child Spacing for Miscarriage = (Due Date + Average Timing of Birth vs. Due Date) – Prior Event (Birth, Loss, or Wedding).  Also, the next child’s spacing is counted from the Loss Date, not the Prior Event.

Losses w/ Minimal Data   When we know a couple suffered a loss, but we don’t have any real data to go on—e.g., Anna’s 2009 / 2010 Miscarriage—Duggar Data factors in that data by slightly decreasing the spacing for the subsequent child.  Specifically, the next child’s spacing is reduced by 6 Weeks (42 Days), by the Gestational Age at Prior Miscarriage, if known.  I’m using 6 Weeks as the default, since most losses occur by Week 6.

Example #1   Josiah + Lauren suffered a loss (Asa), then welcomed Baby Bella.  Asa was due on June 5, 2019, and Lauren miscarried on October 4, 2018.  This falls within “Losses w/ Known Due Date + Loss Date.”  As a result, Si + Lauren have two child spacing data points labeled as ‘Marriage–to–Firstborn’—

331 Days for Asa   (Asa’s Due Date [6–5–19] + Average Delivery vs. Due Date [9 Days Based on Lauren’s Data; Prior to Bella’s Birth, Family Data Was Used] – Prior Event [Josiah + Lauren’s Wedding, 6–30–18]) 

400 Days for Bella   (Bella’s DOB [11–8–19] – Prior Loss Date [10–4–18])

Example #2   Anna (Keller) Duggar suffered a miscarriage after Mackynzie, but we don’t know when, etc.  The Predictor factors in this loss by slightly reducing the spacing for Anna’s next–born child (Michael).  We don’t know how far along Anna was when she miscarried, so it assumes 6 Weeks.  Michael’s Spacing will thus be 573 Days—i.e., Michael’s DOB –Mack’s DOB (615 Days) – 42 Days.

New Method of Predicting The Future Pace of 1–Child Couples—

One Child Couples are a conundrum, because they have a single data point to use...  But at the same time, it’s unlikely that they’ll maintain their Marriage–to–Firstborn Spacing for the duration of the woman’s fertility.  An earlier Predictor addressed this with a new rule...  If a couple’s first child arrived relatively quick, then Child 2′s DOB would be set at Child 1′s DOB + (1.5 * Marriage–to–Child 1 Spacing).  This dealt with the issue of grossly overestimating the future pace of 1 Child Couples, but it always bothered me that the1.5 Multiplier wasn’t data–based...  It was arbitrarily–selected, based on what I thought was ‘reasonable.’

Finally, Predictor 2020 fixes the problem!  One Child Couples’ next spacing will still be based on Marriage–to–Firstborn Spacing and a multiplier; however, that multiplier is now data–based.  I’ve calculated each family’s typical ‘slow–down’ from Child 1 to Child 2, and will use that as the multiplier.  So, the new formula is...  Child #2′s DOB = Child #1′s DOB + (Average Slow Down [Family’s Data] * Marriage–to–Firstborn Spacing).

Example   Per the data, a typical Bates Couple’s Child 1–to–Child 2 Spacing is 1.68x longer than their Marriage–to–Firstborn Spacing.  Based on this, Carlin + Evan’s—who had Layla only 251 Days into their marriage—are due to welcome Stewart #2 1.68 * 251 Days = 423 Days after Layla.

Avoiding Skew from Marriage–to–Firstborn Data—

Under the Old Predictor, a couple’s Procreative Pace was calculated by averaging all their child spacings, including Marriage–to–Firstborn. This was slightly problematic for couples with only a few children, as the Marriage–to–Firstborn spacing seemed to skew the average much lower than it otherwise would be. (For almost all couples, Marriage–to–Firstborn is by far their shortest spacing).

Predictor 2020 eliminates this problem. Marriage–to–Firstborn will no longer with averaged in with the other spacings. A couple’s Procreative Pace will be set at the average of all their other spacing. When a couple has only one child, the multiplier is used to set a tentative pace. When they actually announce Pregnancy #2, the estimated pace (based on the due date for that pregnancy) will substitute in (and later be updated again when the baby actually arrives). Thereafter, each subsequent spacing is averaged in, thus possibly shifting the pace over time.

Simpler Way of Dealing w/ Late Events—

Prior Predictors had this nifty feature called “dynamic adjustment,” which was intended to preemptively increase the couple’s baseline spacing based on the lateness of their next pregnancy.  This was cool, but also really confusing...  I’ll admit that even I sort of forgot how it worked.

Now, I’m going back to basics.  When an event is late, it will simply be pushed forward by a certain amount of Standard Deviations (SDs).  Previously, this was done by increments of 1 (e.g., 1 SD, 2 SDs, 3 SDs).  Now, it will be done by 0.5 increments (0.5, 1.0, 1.5, 2.0).  Additionally, the Predictor will still adjust to take into account this longer spacing; however, the ‘dynamic adjustment’ only kicks in for the next pregnancy.  So, now I can clearly state how ‘late’ a pregnancy is; none of this confusing ‘dynamic’ stuff.  Hurrah!

A Rule for Deciding When A Late Event Won’t Ever Happen—

Many of you have asked if there’s any point at which I’d assume, say, Jana will never court of the Keilens will never have children.  I’ve thought it over, and the New Predictor includes this as a feature.

Here’s the rule:  If the event is 5+ SDs and 5+ Years overdue, the Predictor will assume that, actually, it’s never going to happen.  Also, just FYI, this applies to courtship and pregnancy announcements.  If someone’s really late to give birth, the Predictor won’t give up and decide the baby isn’t ever coming.  Likewise, it won’t assume that a long engagement means the wedding is off.

Example   The Maxwells have a 38–Year–Old daughter named Sarah.  The data indicates that she was due to court in 2006, and is currently 9.1 SDs and over a decade late to court.  At this point, the Predictor thinks she’ll remain single.  By contrast, it hasn’t yet given up on Jana courting or Michaela + Brandon having children.  Jana is >5 Years, but only 3.5 SDs, Late.  And the Keilens are 46 SDs Late, but haven’t yet been married for 5 Years.   

Not Double–Counting The C–Section Delay—

Awhile back, the Predictor began assuming that a C–Section would slow down a couple’s ordinary pace by 93 Days.  While I added time to a couple’s pace to account for C–Section, I didn’t do anything to prevent the resulting spacings—which might be ~93 Days Longer than they otherwise would have been—from skewing the family data.

This isn’t a huge change...  After a C–Section, I will continue adding 93 Days to the affected couple’s expected pace, and now will also reduce the subsequent Child Spacing by 93 Days.  This is intended to remove the delay caused by the C–Section from the family data, on the theory that that spacing would’ve been slightly quicker but–for the C–Section.

Example   Jill had a C–Section with Israel.  Sam arrived 824 Days Later.  Sam’s Child Spacing won’t be 824 for Predictor 2020, but 731 (or 824 – 93); however, since he arrived by C–Section also, the Predictor will continue to add 93 Days to the Dillard’s expected pace.    

New Predictor Families (and Room to Expand)—

The Predictor has expanded!  Predictor Families now include—

The Duggars 

The Bateses

The Maxwells

The Kellers  (Quiverfull Only)

The Bontragers

Sierra + Mark

Bethany + Dav

Additionally, because of the way the algorithm is now written, it is super simple to add new families or couples.  I could even have the Predictor run using all of the data from all families, rather than family–specific data.  Nifty!    

According to Predictor 2020.

I’m still pretty enthralled with my new toy, and I thought it would be fun to do a Post that’s like the Next 6 Months, but on steroids.  Here’s what Predictor 2020 is forecasting for all of the Predictor Families—the Duggars, Bateses, Maxwells, Kellers, and Bontragers—as of March 14, 2020...

What Just Happened  (Jan. 1–Mar. 14, 2020)—

01–07–20   Grace “Gracie” Annette (#1) born to John + Abbie Duggar. 

01–18–20   Simon Peter (#6) born to Christopher + Anna Marie Maxwell.

01–25–20   Caleb Alexander (#3) born to Joseph + Elissa Maxwell.

01–31–20   Layla Rae (#1) born to Carlin (Bates) + Evan Stewart.

03–08–20   Joseph (#12) born to Esther (Keller) + John Shrader.

03–08–20   Katie Bates + Travis Clark started courting.  (Estimated) 

What’s Next  (Mar. 15–Dec. 31, 2020)—

03–16–20   Michaela (Bates) + Brandon Keilen announce Pregnancy #1.

03–20–20   Carson + Carolina (Bowers) Bontrager announce Pregnancy #2  (2 SDs Late).

03–24–20   Alyssa (Bates) + John Webster announce Pregnancy #4  (2 SDs Late).

03–31–20   Smith #2 (Kolter Grey) born to Tori (Bates) + Bobby.

04–26–20   Anna Elizabeth Maxwell starts courting  (2 SDs Late).

05–01–20   Jill (Duggar) + Derick Dillard announce Pregnancy #3  (3 SDs Late).

05–10–20   Keller–Waller #5 born to Priscilla (Keller) + David.

06–07–20   Joy (Duggar) + Austin Forsyth announce a pregnancy.

06–10–20   Josie (Bates) + Kelton Balka announce Pregnancy #2.

06–14–20   J. Bontrager–C. Bowers #2 born to Joshua + Cassidy.

06–19–20   Maxwell–Bontrager #2 born to John + Chelsy.

07–03–20   Per their registry, Nathan Keller + Nurie Rodrigues marry.

08–10–20   Webster #4 born to Alyssa (Bates) + John.

08–11–20   Nathan + Melanie Maxwell’s quiver is presumed complete.  If it’s not, this is when they’d be due to announce Pregnancy #8.

08–15–20   If Michaela (Bates) + Brandon Keilen haven’t yet announced Pregnancy #1, their ESOQ will drop to 0 Children.

09–01–20   Keilen #1 born to Michaela (Bates) + Brandon.

09–18–20   Jessa (Duggar) + Ben Seewald announce Pregnancy #4.

09–20–20   Joe + Kendra Duggar announce Pregnancy #3.

09–29–20   C. Bontrager–C. Bowers #2 born to Carson + Carolina.

10–02–20   Lawson Bates starts courting  (2.5 SDs Late).

10–06–20   Anna Elizabeth Maxwell gets engaged.

10–17–20   Nathan Bates starts courting  (2 SDs Late).

10–30–20   Carlin (Bates) + Evan Stewart announce Pregnancy #2.

11–13–20   Balka #2 born to Josie (Bates) + Kelton.

11–13–20   Travis Clark proposes to Katie Bates.

12–02–20   Dillard #3 born to Jill (Duggar) + Derick.   

12–09–20   Forsyth #2 born to Joy (Duggar) + Austin.

12–21–20   Chris + Anna Marie Maxwell announce Pregnancy #7.  (Her cancer is not factored into the Predictor.)

12–27–20   Erin (Bates) + Chad Paine announce Pregnancy #5.

Nothing in 2020 For—

Duggars—Josh + Anna, Jana, John + Abbie, Jinger + Jeremy, Josiah + Lauren, Jedidiah to Josie

Bateses—Zach + Whitney, Trace, Jackson to Jeb

Maxwells—Sarah, Jesse, Mary

Kellers—Anna + Josh

Bontragers—Mitchell + Bryn, Allison, Denver to Rebecca

I’m so excited, you have no idea.  It’s really pushing the limits of my computer’s computing power, but it works for the Duggars and Bateses.  Soon will work for the Maxwells, Kellers, Rodriguii, and Bontragers, as well.

How Do Erin’s Miscarriages Factor Into Her Data?

Very, very, very good Ask.  I was actually hoping someone would Ask this.  Erin had 3 Miscarriages in 2014, followed by 4 Live Births—Carson (2015), Brooklyn (2016), Everly (2018), and Holland (2019).  Erin + Chad have one Child Spacing data point for each live birth, obviously…  But what about the miscarriages?

Ideally, we’d have enough information to assign a ‘Theoretical’ Spacing to each loss, too.  To do so, we’d need to know a Due Date, Loss Date, or both.  Sadly, in this case, we only have the information for one of Erin’s three miscarriages—the first one.  For Erin’s 1st Miscarriage, we know that she was due on or about October 15, 2014—i.e., a week before Whitney (w/ Bradley).  (Whitney was due on October 22, 2014.)  As for the Loss Date…  Erin found out she was pregnant in February 2014.  (Erin + Chad married on November 2, 2013.  Erin discovered she was pregnant 3 Months Later.)  Unfortunately, trouble arose at the very first ultrasound, which “showed only an empty sac.”  It’s possible that it was simply too early to visualize the sac, so Erin’s OB–GYN did “several ultrasounds,” plus  blood tests, probably over a period of weeks.  Ultimately, Erin did miscarry, and underwent a D&C.  Apparently, this all occurred by March 17, 2014, when Chad announced the loss on their personal blog…  From all this, we can determine a rough loss date range of mid–February to March 17.  (Duggar Data uses March 1, 2014 as an estimate.  If I knew the exact date of the D&C, that’s the date I’d use.)  That allow us to calculate a spacing for Miscarriage 1, as follows—

Child Spacing for Erin’s 1st Miscarriage = Projected DOB (i.e., Due Date + Erin’s Typical Delivery vs. Due Date [–27 Days]) — Erin + Chad Wedding Date

… which works out to 320 Days.

Since we don’t have Loss Dates or Due Dates for Miscarriages 2–3, there is no way to calculate Theoretical Child Spacings.  Instead, the Predictor assumes a loss at 6 Weeks (42 Days), and reduces the next child spacing by that much.  It isn’t a perfect system, but it’s the best we can do with limited data.  In the case of Erin + Chad, that next spacing is Carson’s.  It’s calculated as follows—

Child Spacing for Carson = Carson’s DOB — 1st Miscarriage Loss Date — 42 Days for Miscarriage #2 — 42 Days for Miscarriage #3

… which works out to 355 Days.

Since there aren’t any intervening miscarriages, the rest of Erin + Chad’s child spacings are simply the difference between the two DOBs—

Child Spacing for Brooklyn = Brooklyn’s DOB — Carson’s DOB

Child Spacing for Everly = Everly’s DOB — Brooklyn’s DOB

Child Spacing for Holland = Holland’s DOB — Everly’s DOB

Ultimately, the Paines’ Child Spacings work out to be as follows—

Miscarriage #1   320 Days

Carson   355 Days

Brooklyn   450 Days

Everly   601 Days

Holland   606 Days

For purposes of the Bates 2nd Child Multiplier, Miscarriage #1 and Carson are both treated as a 1st Spacing, while Brooklyn is treated as a 2nd Spacing.  For purposes of Procreative Pace, all spacings other than those deemed to be 1st Spacings (Miscarriage #1 and Carson) are averaged.  So…  Erin + Chad’s pace is 1 Child Every 552 Days, as or right now.  

It’s New, Improved, and Better Than Ever  (Part 1)

The Predictor is Duggar Data’s favorite forecasting tool.  It’s a massive Excel workbook, written by yours truly, that tracks all of the data—i.e., dates—about relationships and pregnancies, crunches that data, and then plugs all of the data into an algorithm to predict future events.  Predictor 1.0 hit the scene almost 2 Years Ago...  Since then, I’ve improved it several times, but Predictor 2020 is by far the most significant revision.  Honestly, it’s a total rebuild, which incorporates more data than ever before, tweaks the algorithm to hopefully be more accurate and realistic, and allow for future expansion.  (Now, I can easily add new families, or make specific predictions for the 4th Generation!)

Here’s a quick overview of Predictor 2020—what’s the same, what’s different.  Part 1 focuses on what’s the same.  Part 2 focuses on what’s changed.

What’s The Same—

Like all Predictors, Predictor 2020 creates personal forecasts for each Duggar, Bates, Maxwell, etc., based on data from that individual and their family.

Like previous versions, Predictor 2020 is fueled by Averages (AKA Means) and Standard Deviations (SDs).  Average (or Mean) is a measure of typicality, which identifies a specified value as the most ‘ordinary’ value within a given data set.  It’s calculated with the formula:  Average = (Sum of All Data Points) / (# of Data Points).  While all sorts of fancy means exist in statistics, Duggar Data uses an ordinary arithmetic mean for all purposes.  (I don’t claim to be very statistically rigorous!)  Standard Deviation (SD) is the other data type used in the Predictor, and comes into play whenever an event is ‘late.’  SD is a measure of variability, which uses a single value to represent how consistent data points are within a specified data set.  If you’re nostalgic for your high school statistics class, you can read all about the SD formula here.

Predictor 2020, and all the previous versions, are also chronological.  By this, I mean that each event builds on the next.  For individuals with no data to speak of—e.g., Josie Duggar, who is far too young to be in a relationship—it starts by calculating a Courtposal Date.  Then, it calculates a Proposal Date, assuming a Duggar–average length courtship.  A Duggar–average length engagement adds onto that, and you get a projected Wedding Date, which is adjusted to a nearby Friday or Saturday, if needed, etc., etc.

Here’s a brief summary of how Predictor 2020 calculates each date—

Courtship Start Date is based on age, and is sex specific.  Females will start courting at their family’s Average Age at C.S. for Females (Born–In and In–Laws), and males will start courting at their family’s Average Age at C.S. for Males (Born–In and In–Laws).

Engagement Date = Courtship Start Date + Average Length Courtship, with average length being calculated from the relevant family’s data.

Wedding Date = Engagement Date + Average Length Engagement, per the relevant family’s data.  If necessary, the date is then slightly adjusted to fall on the closest Friday or Saturday.

Pregnancy Announcement #1 = Wedding Date + Average Marriage–to–Firstborn Spacing – Average Timing of Birth (vs. Due Date) – (280 – Mean Timing of Pregnancy Announcement), all based on family data.

DOB of Child #1 = Wedding Date + Average Marriage–to–Firstborn

Subsequent Pregnancy Announcement = Last Birth + Average Spacing Between Births – Average Timing of Birth (vs. Due Date) – (280 – Average Timing of Pregnancy Announcements), all based on the specific couple’s data (if available) or the relevant family’s data (Duggar, Bates, etc.)

Subsequent Children’s DOBs = Last Birth + Average Child Spacing

Fertility Cut–Off is based on the age at which a woman’s mother’s final child was born.  Age 40 is used if Duggar Data can’t find information on the woman’s mother, her mother wasn’t quiverfull, or her mother hasn’t yet completed her own quiver and she’s still under Age 40.

Note that, when real data is available, the Predictor always uses that instead of it’s projection.  So...  The Predictor thought Katie + Travis would begin courting at a specific time, and based all subsequent events on that date.  When Katie + Travis actually announced their courtship, I added the real date (or, in this case, my best estimate) in, and the Predictor recalculates everything based on that.

Additionally, with Children’s DOBs...  Once a pregnancy is announced, the due date provided by the couple (or my best estimate) controls the projected DOB, not the longer formula listed above.  Once there’s a know pregnancy, the DOB formula is quite simply:  Due Date + Typical Timing of Birth (vs. Due Date). 

How Did The Vuolos 2nd Pregnancy Announcement Shift So Much?

ICYMI—There’s an entirely new Predictor!  So, that is the main reason.  As for exactly what changed with Predictor 2020 that caused this…  It’s the rules for predicting Child 1–to–Child 2.

Felicity arrived 621 Days into the Vuolo marriage.  As such, the Prior Predictor set the Vuolos Procreative Pace at 621 Days, the average of all their spacings. (Air quotes around “average,” since it’s really not an average.  It’s the only data point, thus far.)  Note that Felicity isn’t treated as a Honeymoon Baby, and thus their spacing was just set at 621 Days, not at 1.5 * 621 Days.  At that 621–Day pace, Jinger + Jeremy are already late to announce Pregnancy #2.

Predictor 2020 does two things differently, here—

Did Away w/ All Special Rules for Honeymoon Babies.  All 1 Child Couples’ future projected pace is calculated the same way.  No special rule to ‘slow down’ a couple after a Honeymoon Baby.  (It is so hard to define “Honeymoon Baby,” anyway, so that’s what motivated me to do away with those special rules.)

Uses Data to Estimate The Slow Down From Child 1 to Child 2.  The New Predictor sets the Procreative Pace of a 1 Child Couple with a very simple formula:  Marriage–to–Child 1 Spacing * a Data–Based Multiplier, which is the average slow down from Child 1 to Child 2, as seen in other couples in the same family (Duggar).

As of March 2020, your Average Duggar Couple’s Child 1–to–Child 2 Spacing is 1.78x Longer that their Marriage–to–Firstborn Spacing. Thus, Predictor 2020 set the Vuolos pace at 621 Days (Marriage–to–Felicity) * 1.775 (Duggar Multiplier)  = 1,103 Days.  As such, Predictor 2020 doesn’t expected Vuolo #2 to arrive until Felicity is 1,103 Days Old…  At that pace, Jinger + Jeremy aren’t even overdue to announce, yet.  They’ll be on–time if they announce in January 2021.

Wait.  Explain the C–Section Delay Again, Please?

Yeah, I should have explained that better.  Let me try again...

For quite awhile now, the Predictor has increased a couple’s expected spacing by 93 Days after a C–Section.  That’s based on a medical journal study I found, which showed that, on average, it takes 93 Days Longer to conceive after a C–Section (vs. a vaginal birth).  That study also showed that this 93 Day delay will go away if a woman who once had a C–Section later has a successful VBAC—so it’s the woman’s most recent delivery that drives things, not the fact that she once upon a time had a C–Section.

After a C–Section, the Predictor continues to impose the 93–Day delay, when it forecasts the next pregnancy.  The question arises, however, in how to treat the actual, post–Cesarean spacing, when that woman’s next child is born.  Prior to this, the Predictor just treated that spacing like any other...  It didn’t modify it, at all.  This is problematic, however, since there is a good chance that that spacing was longer than it otherwise would have been, due to a C–Section immediately prior.  Basically...  That spacing is a bad representation of the woman’s ‘natural’ pace, since it’s delayed by a condition that may not exist in later pregnancies—a prior Cesarean delivery.  With this in mind, Predictor 2020 modifies any post–Cesarean spacing by –93 Days, to prevent delay caused by the C–Section from impacting the woman’s average pace too much.  So, in summary—

After a woman has a C–Section, the Predictor delays the next Pregnancy Announcement / Birth by 93 Days, on the theory that that C–Section may slow her down due to a longer recovery time, or whatever.

Then, when a woman actually gives birth after a C–Section, the Predictor subtracts 93 Days from the actual spacing, so that the couple’s pace will not be skewed low due to delays solely attributable to a prior C–Section.  This modified spacing is what is used to calculate their Procreative Pace, going forward.

If the woman’s post–Cesarean delivery was a successful VBAC, then the Predictor forecasts her pregnancy like normal...  Next Child’s DOB = The Latest Child’s DOB + Procreative Pace.  If, however, she had another C–Section, she would again be delayed by 93 Days.  Her Next Child’s DOB = Latest Child’s DOB + Procreative Pace + 93 Days.