How have estimates of the deaths in WWI and WWII changed over time?

Question

I am curious about what the generally accepted death figures in the two world wars were at times between the wars and the present time.

There are many sources on the internet today which give numbers for the deaths in World War One and World War Two.

For example, this Wikipedia list https://en.wikipedia.org/wiki/List_of_wars_by_death_toll says for World war One:

16,000,000–40,000,000+ (the higher estimate also includes the first victims of the related Spanish flu epidemic who died by the end of 1918. Neither includes the subsequent Russian Civil War)

And says for World War Two:

85,000,000

This article on World War One casualties https://en.wikipedia.org/wiki/World_War_I_casualties says:

The total number of military and civilian casualties in World War I was about 40 million: estimates range from around 15 to 22 million deaths1 and about 23 million wounded military personnel, ranking it among the deadliest conflicts in human history.

The total number of deaths includes from 9 to 11 million military personnel. The civilian death toll was about 6 to 13 million.1 The Triple Entente (also known as the Allies) lost about 6 million military personnel while the Central Powers lost about 4 million. At least 2 million died from diseases and 6 million went missing, presumed dead. This article lists the casualties of the belligerent powers based on official published sources.

This article on World War Two casualties

https://en.wikipedia.org/wiki/World_War_II_casualties#:~:text=An%20estimated%20total%20of%2070,war%2Drelated%20disease%20and%20famine.

says:

World War II was the deadliest military conflict in history. An estimated total of 70–85 million people perished, or about 3% of the 2.3 billion (est.) people on Earth in 1940.1 Deaths directly caused by the war (including military and civilian fatalities) are estimated at 50–56 million, with an additional estimated 19–28 million deaths from war-related disease and famine. Civilian deaths totalled 50–55 million. Military deaths from all causes totalled 21–25 million, including deaths in captivity of about 5 million prisoners of war. More than half of the total number of casualties are accounted for by the dead of the Republic of China and of the Soviet Union. The tables below give a detailed country-by-country count of human losses. Statistics on the number of military wounded are included whenever available.

Recent historical scholarship has shed new light on the topic of Second World War casualties. Research in Russia since the collapse of the Soviet Union has caused a revision of estimates of Soviet World War II fatalities.2 According to Russian government figures, USSR losses within post-war borders now stand at 26.6 million,[3][4] including 8 to 9 million due to famine and disease.[4]5 In August 2009 the Polish Institute of National Remembrance (IPN) researchers estimated Poland's dead at between 5.6 and 5.8 million.[6] Historian Rüdiger Overmans of the Military History Research Office (Germany) published a study in 2000 that estimated the German military dead and missing at 5.3 million, including 900,000 men conscripted from outside of Germany's 1937 borders, in Austria, and in east-central Europe.[7][8] The Red Army claimed responsibility for the majority of Wehrmacht casualties during World War II.[9] The People's Republic of China puts its war dead at 20 million,[10] while the Japanese government puts its casualties due to the war at 3.1 million.[11]

So, if there have been relatively recent revisions in numbers of deaths in World War Two, I wonder what the estimates were in earlier times.

Was there ever a time when it was believed that 50,000,000 people died in World War Two, or 100,000,000? Was it ever estimated, for example, that between 52,842,284 and 75,182,683 persons died in World war Two?

Was there ever an estimate that, for example, between 5,493,286 and 12,486,328 people died in World War One?

I am curious about what the generally accepted death figures in the two world wars were at times between the wars and the present time.

Answer 1

Estimates do change over time. There is a typical evolution to this modern-day conundrum:

Phase 1: The War is Still Ongoing

Almost always, opposing losses are over-stated and own losses are under-stated. Over-stating opposing losses is practically guaranteed, driven by battlefield confusion and a desire to prop up the home-front morale. Likewise, own losses may be not yet compiled and also under-stated (or not stated) due to "operational security," for both reasons of hiding weakness from the enemy and also propping up home-front morale.

Sometimes one or more sides can get carried away in over-stating their opponent's losses - it becomes a pandora's box that can't be easily shut after being opened, due to the political momentum.

Numbers published during this phase are also "anchors," in that any future adjustments or research has to relate to that initial anchor, no matter how far off that initial claim was.

Ukraine is currently in this stage. The numbers that have come out are not reliable and are incomplete, and neither side wants to be honest at this point because of operational security and home-front morale.

Phase 2: The War is Over, Rational Study Begins

Now historians take over. Initial claims get scrutiny as records are released. If a combatant had good record-keeping (and those records survived), these are researched and published. Statisticians may also give it a go with some math models, which can be refined with more inputs and correlation to known records. It can also be a matter of counting graves.

Some Examples

One easy-to-study example is the Axis surrender in Tunisia in May of 1943, and specifically how many Axis prisoners were taken. Liddell Hart [1] compiled these numbers from different sources:

• A report from General Alexander to General Eisenhower's HQ on May 12 claimed 100,000 prisoners, expected to rise to 130,000.
• A follow-up report from Alexander to Eisenhower claimed 150,000.
• Alexander published a despatch after the war that claimed 250,000.
• Churchill, in his memoirs, claimed "nearly a quarter million."
• Eisenhower later claimed 240,000, of which 125,000 were German.
• A report from Army Group Afrika to Rome on May 2 reported a ration strength of between 170,000-180,000 troops.

Liddell Hart tended to believe the logistics reports the most. The admin staff is likely the most aware and honest about the number of mouths they are feeding and have the least incentive to over-state or under-state those numbers. Liddell Hart goes on:

Here it is worth remark that much larger discrepancies still, between the last known German ration strength and the Allied claims about the number of prisoners captured, were manifest in the final stages of the war.

This kind of data is likely only to be found by researchers after the war, who are seeking these records and that those records can still be found.

Sometimes records that come to light later on can spark a controversy as well, if they disagree significantly with the existing narratives.

Another example is the controversial book, John Mosier's The Myth of the Great War [2]. The thesis of that book was to deduce what was really happening on the First World War battlefields, when records from the German side are used to correct the greatly inflated British claims of German losses.

[1] History of the Second World War. B.H. Liddell Hart, c 1970.

[2] The Myth of the Great War. John Mosier, c 2001.