A somewhat belated reply
True, but you are advocating huge investment (hammers and gold) in your own few cities ( CE/CorpE/Kremlin economy) and then researching a tech that blasts any captured cities into oblivion. That investment takes a great deal of time to research techs I don't need, consumes GPs for the corps that I can use in other ways (such as a golden age or two) and then sucks immense amounts of gold used to rush buy stuff and spread corps. How fast does all this investment pay back what was invested so you're making a profit? Furthermore, you gain little economically thereafter since you either blast the city into the ground or give it away effectively when you capitualate the AI.
Your economy plateaus , albeit at a high level.
My approach is quite different and I get a huge economic boost from,
a) not researching at least some of the techs you need to
b) building military units dierectly instead of investing in infrastructure, corporations and then building them
c) Using the GPs for other purposes, maybe golden ages
d) starting the war much earlier and keeping more of the cities captured many of which will be productive and help finance the war (gold, beakers and EPs) and produce military units. Using SP means distance and colonial costs are zero, so I can pick and choose what cities to take and keep for their rich developed tiles, wonders, buildings and settled GPs. Some AI cities will be better than many of my own, so
my economy grows strongly as I attack and capture more resources. At the end of the game my economy with many cities could be stronger than your few hyped up core cities with the CE/CorpE/Kremlin development. We would have to do a detailed analysis to decide that and I don't think that's worthwhile, besides I don't want anymore of highly imaginative hand waving
Some AIs can be capitulated to avoid WW (if not in PS) and the tedium of ploughing through AI culture. But that is an option for me rather than a necessity for your CE/CorpE/Kremlin economy running FS. If you take on other cities they are just a gold drain, either due to colonial costs or because you have to make a heavy investment installing corps and rush buying buildings that will not have time to pay back the investment, so that's a clear lose-lose situation.
It is somewhat ironic that you are worried about how many hammers I use here when you a) are prepared to spend fabulous amounts of hammers/US gold on each of your own cities and b) claim that you can outproduce my economy by a huge margin anyway. Why ever would you be worried about a few hammers when you can produce thousands every turn? Efficiency doesn't come into it only brute force. Capturing juicy AI cities and using them to build replacements makes up for at least part of the inefficiency
This is not my experience perhaps someone can read the relevant code for us. I have found that air combat obeys Lanchester's Law better than anything in this game. In other words numbers are more important that quality given the way air combat works. Even if the AI has a few nicely promoted jets on interception my carriers full of fighters will shoot them all down even at some loss
Flight is immediately after Combustion for me and I upgrade some of my galleons to transports (cheap and effective against figates) and build destroyers while researching it. Then I build carriers (in drydocks) and fighters in inland cities. That doesn't take long at all and Kremlin whipping means the carriers and destroyers surge out of the drydocks, and the fighters can fly to the carriers while they move into position. You have completely misjudged the time it takes to build a modern oil fueled navy and airforce. I find transports with frigates and galleons enough to give naval superiority against frigates and SoL even when they have superior numbers. The odd upgrade of a frigate to destroyer helps against airships and top defender but is expensive. I tend to keep frigates around as a counter to obsolete units and for bombardment for quite a long time.
I don't play deity and I doubt I ever will. I win comfortably on immortal using this and other strategies.
Nukes are the most cost effective mechanism to cause damage to the AI if it has large stacks otherwise they are not worth the hassle. I agree the SE/EE/FE combo is one of the most powerful strategies and I am comfortable playing it but I like other strategies as well including using corps in a SE. Fighters are available earlier and are more flexible than tac nukes, especially when combined with espionage, plus there is no diplomatic penalty for each time you use one nor can they be stopped by a UN resolution.
So my little clam city (founded in 500 AD) and which whipped/built all its own infrastructure, which in the meantime has been used to draft 6 muskets and rifles, whipped 3 galleons, 3 cannons and a frigate BEFORE it whipped the carrier is less profitable than your desert city (founded in 1850AD)? I don't think so. Those 51 hammers/ turn you've just magicked out of the sand are not FREE. They are the result of an astonishing amount of gold and hammers that the rest of your economy has lavished on it. I repeat my question, have you analysed the pay back on that late game investment? The "little bugger" might be able to build a tac nuke every 5 turns but I wonder if it would not have been better to just buld the nukes in another city, certainly a lot less effort and micomanagment.
You have the temerity to accuse me of picking a lame example. I can assure you that I will have an average of at least 2 clam cities (or equivalent) every game. I know the power of corps, you are trying to teach your grandmother to suck the proverbial eggs. You are overstating the power of the CE/CorpE/Kremlin economy and undersetimating the alternatives. My argument is not that you can't win that way, you can and so could I, but you need to justify why it is so much better than all the alternatives including the one I put forward. I see the CE/CorpE/Kremlin economy as just one option and not the king of all economies.
Touche ! Amusing, but not true. I am very happy to use a wide variety of economic and military strategies. I think I have have tried just about all of them. That is why I can say with confidence that you are overstating the power of the CE/CorpE/Kremlin economy. I've been there and done that - and then thought why did I bother? I could have done that quicker by just just grabbing the AI by the throat and avoiding all that investment and re-investment of profits to get even bigger profits. Few things are more profitable than a juicy AI capital!
You are missing out again on the power of a CorpE. The singlest biggest gain you get with a heavy corp E is not the territory, as such, it is the the resources you gain. Capping a large AI can net me +20

in every city. If I'm nuking to cap out the AI I just avoid (as best as possible) irradiating the resource tiles I want and just take and extort away the resources I want. This gives me an instant boost to my interior and allows to me move to victory quicker. When I've done comparison games (playing through twice), the CorpE investment allowed for ~25 turn sooner wins on maps where I deemed it to be optimal than opting for a SP driven war machine. Games were (re)played in random order from the turn before lib; 2 losses that occurred with SP did not with CorpE, but both of those were from a SP first run.
I also get advantages:
a.) I don't necessarily need to research techs which you do (obviously there are no techs that are a complete waste for either of us): Constitution is a low priority for me so I can go chase free GP at Sci meth while you (unless you are doing something I'm missing) want Con asap if you lack the Mids. I can ignore democracy if I have the mids and eventually the UN; you need the building. I can ignore communism if the AI takes it and the Kremlin (in which case I have target city); you outright need it for SP.
b.) Corp execs are 100

and 100

; if the map is good for it, this is repaid in under 2 turns. Low value buildings can just be whipped in (indeed if I have the actual clam city I will have founded long ago, whipped in the CH, the market, and hopefully the forge long, long ago). All told, I have yet to find a city which fails to break even in a CE prior to 4 cycles of the whip.
c.) Fair enough, you could spend 4 GP on 1.5 more GAs than I typically take. Of course your GAs are less powerful as you have fewer one

tiles and you burn more of the bonus

into

.
d.) No it won't. My extra trade route means large overseas cities pay for themselves up to the point where I have 6 such cities; no questions asked; all of my trade

is captured for with full multipliers; you burn a large percentage as culture by being "slider independent" and more because you don't have a full set of

multipliers. I actually grow my economy faster because not only do I get the city inputs, I get exponential growth in Corps efficiency as redundant resources are FAR more viable for me.
In reality most cities, even crappy little AI ones overseas pay extremely well with 5 free trade routes (20

off the top); assuming I capture either the bank or market/grocer (an odds on bet), that gives me 30

which pays for a huge amount of maintenance. Once we toss in a harbor or the full MGB set I can come out ahead with any city. Resources dwarf all of this but then I have the options of using vassals for those. Even more fun, any city I take is an instant production powerhouse. I can build whatever I need without having to worry about airlift issues (like you do if the conquest pop is not enough to whip in an airport), without having to set up production buildings, and without having to fight for cultural tiles. If I need an airhead that is two turns and I have it. If I need the 5 settled GG with an Mil Acad city to pump out CR tanks, I can do that even if it has zero tiles to work. I have far more options than you. Once we drop in the corps for a whopping 350

per exec (aka peanuts) any city, anywhere on the globe is profitable for me.
I worry about efficiency because while I can beat any economy into the ground if I get the full CorpE up and running; the trick is
getting there. At industrialism/flight/combustion/fission I may not have the juggernaut online (and I may never even try to get it online). I just have the
option to build out the juggernaut. A quick jump down industrialism -> fission -> rocketry is actually game ending moving to circumvent getting the juggernaut fully ramped up. I do it because it can be the fastest/surest way to win.
You should play deity, I think you'd do better than me there.
I do not disagree with you, at all, about the strength of the SE/EE/FE combo nor the costs of using nukes. There are situations where it is optimal, there are situations where it is not. I admit I'm biased against EE for my own play (though I will play them now and again) but some situations simply are better resolved with a quick run to nukes and glowing your way to victory.
I also play all economies. I've been on a SE(P) kick of late (this may have something to do with playing Sal, Hatty, and an isolated Toko). I know where the strengths of SE lie and I know where the strengths of a properly leveraged CE lie. SE hits peak earlier and has a faster rise to peak, but it is weaker long term. Often selling out to the short term is the wiser course and it would not surprise me if SE/EE/FE is on average the best economy for the entire course of the game; however it is among the least forgiving economies to run whereas CE/CorpE is among the most forgiving. Thus when I say nukes + rushbuy is an easy way to win this, it is not that is the only or even best way to win this, just it is an easy to learn method to win there. There are times when it
is optimal, but not always.
Actually, yes I have analysized the payoff for founding such cities. A coastal clam will also have been founded in 500 AD by me. I will have whipped in a Grain/CH/Market/lib (because it is cheap enough to give a return quick)/Grocer and most likely a forge (definately if Ind) possibly even a bank (if FIN). I normally do rushbuy or corps build the factory and the airport, but those are coming after they pay for themselves in a short time frame (if they won't, particularly the factory) then I'm just not going to build it. A coastal airport, BTW, pays for itself in two whip cycles ... and just happens to let me use this city to spam airpower or self-airlift.
I am not overstating the potential power of Kremlin/CorpE/CE. If anything I
understate them. Shall I go WB a 7 trade route clam city with 7 overseas pop 20 cities feeding into it where I control 50% of the world's resources? Maybe throw in a triple holy city WS shrine with the AP and SM? You have 2 clam cities per game where it is
literally nothing but coastal tiles and the clam? No brown tiles, no tundra/desert windmills? No desert resource tiles?
Even if we grant this is typical, when I'm going for conquest I have 5-20 crappy filler cities and my only question is "do I really
need this city to do anything?"
The investment in a terminal corpe is peanuts compared to the costs of building more airpower/units to take the city. Let's just say I can use two tac nukes and 4 CG defenders, on average to take and hold a city. In terms of supporting units I need 1 transport and 1 SSN; total cost of 1,575 :hammers. A naval assault costs about 6 planes (between losses and amortizing the sunk costs over all the cities taken), 2 CVs, 8 units (4 of whom are garrison), and call it one BB, 2 transports and one DD (personally I think the numbers are higher, but let's be generous). All told that is 2,625

per city. Off the top I have 1,050

I can expend on building infra in my conquest just because it is cheaper to nuke and take. 500

gets me a full compliment of MGB. 600 :Hammers: gets me CreCon/CivJ/Sushi (CM)/AlCo. So to bring this sucker back online, costs 50 net

. Of course for a small investment of 520

I can bring a forge/factory/coal plant online. Being generous let's say this city only nets me 100

per turn due to irradiation (including rushbuy). This in turn gives me net break even in a whopping 6 turns. In 10 I've paid for all the infra I will ever want to build; if for some reason it looks really dicey I just leave the bugger with MGB/CH/Harbor and STILL get a better return off the naval assault. With ecology and workers it becomes a joke to mill/mine/WS my way back. Note this is all assuming I can't use slavery to whip in any infrastructure which is an abnormal case as I tend to take or build the CR (or failing that just run Slave outright).
If we include the whip, which is 75% of these types of games for me; Sushi or CM makes my whip far more efficient than yours. Once I drop in CivJ and CM (total cost of 600 :gold); a podunk nowhere city can build itself out with ease.
When I'm near the end I'm just plain spamming units everywhere. I have gold coming out my ears and every city is dropping a tac nuke every other turn (the core cities have sufficient overflow to bring up the marginal cities to this rate).