The 156 Most Populous Worlds Amount to 450 Billion People

[Edit, 2019 April 2: revised calculation here. /Edit]

Someone called Mendrugo is doing an interesting review of BattleTech fiction in stardate order (wrong franchise, sure, but it's easier than saying "chronological according to fictional date rather than real world copyright date"), and he's raised an interesting question: how come worlds like Trellwan, Verthandi and Stein's Folly don't seem to have HPGs when MW1e says HPG stations are located on every inhabited world in the Inner Sphere?

The trick is that the HPG comment comes in a section which distinguishes "inhabited" worlds (and bandit holds) from mere colonies. To wit: while "uncounted other worlds are claimed and exploited by Davion forces," the Federated Suns only possess "about 110 star systems actively settled under its aegis" (page 112). The old House Davion sourcebook (FASA1623, hereafter HD:FS) agrees by setting the number of duchies at 100 to 120. (No doubt the exact number fluctuates with loss and conquest along the House border.)

Unlike the other House books, at most 19 of the 30 worlds listed in the HD:FS Atlas have substantial populations; adding the 9 Chesterton worlds published previously in HL:CC brings the Suns up to 28--exactly the same as the Free Worlds League, and in line with the Draconis Combine and Lyran Commonwealth.

The Housebook Atlases focus overwhelmingly on capitals and other highly populated worlds. By failing to list more such worlds, the HD:FS Atlas rather strongly suggests that the Federated Suns don't have any more to list; and since the Chesterton worlds give the Suns' count parity with the other Houses, it's likely that the other Houses don't have any beyond what they've already listed either.

Now here's a curious thing:

Neither the HD:FS Atlas nor the HS:LC Atlas give population figures. But if we suppose that Steiner's major worlds average midway between Marik's and Kurita's, and if we suppose that Davion's major worlds average midway between Kurita's and Chesterton's, then the (approximately) 156 most highly populated worlds in the Successor States have a combined population of 450 billion people.

The number 450 is remarkable because the number of "inhabited" worlds MW1e gives for each House also adds up to 450.

Another curious thing:

I count about 1900 stars on the Housebook maps, with something like 2000 worlds claimed between the five Housebooks; meanwhile, HD:FS (second page of its History chapter) philosophizes thusly:

Perhaps there are epochs in history when humanity finds an area large enough to grow into--first a country, then a continent, then a world, then four thousand worlds--and remains at that level of expansion until it, too, has been outgrown.

So: greater than 450 billion people, and 2000-4000 colonized planets? This sounds an awful lot like what Robert A. Heinlein said in his book Time Enough for Love, which implies the Inner Sphere has right around 500 billion people across 2000 planets.

I'm tempted to estimate the population of each tier geometrically--450 billion, then 45 billion, then 4.5 billion, then 0.45 billion; and since the divide between "settled" worlds and colonies is at 450 worlds, to put each tier break at (450 - 156 = 294) 294/156ths of the previous tier; so the first 156 worlds average 2.9 billion apiece, then the next 294 would average 150 million apiece, the next 554 would average 8.1 million apiece, the next 1044 would average 430 thousand apiece, and the last 1968 would average 23 thousand apiece.