The Currency System: Gold Coins Are Something You Loot from the Dungeon

[Tier-Group 3, 10th-Floor Reception Room]

"Master, personal secretary: pairing cash payment with the land tax would amount to partially adopting a method much like the so-called 'Kantō Field-Currency Method.' This is a method whereby the tax per unit of area is paid in coin, reckoned in China's Eiraku coin, which is pegged to the koban."

So said Scarlet.

"In that case, it also becomes a question of how to get the coin circulating. This world doesn't seem to have a mint, or anything of the sort."

"I looked into that, and basically it seems dungeon monsters drop koban and one-mon coins directly. In this world, just as the soil is dead anywhere outside a dungeon, mines too are basically dungeons; but rather than merely yielding ore to be dug out, in some dungeons, for whatever reason, monsters drop money when you defeat them. That's why koban and one-mon coins circulate even with no Edo shogunate."

"This isn't a game. And is something that much like alchemy even possible?"

So said the Dungeon Master.

"If it is possible, then it would be replication-summoning from another world by dungeon energy, I'd say. Even so, monsters, of all things… The Master of a dungeon that yields money like that is most likely an MBA, but managing the supply properly looks difficult."

So Marie gave her take. A gold-mine dungeon whose difficulty isn't kept in proper check gets swarmed by adventurers and hunted clean in no time.

"Supply rises too much, you get inflation, and at worst the dungeon itself goes under. It falls too much, you get deflation, or else the adventurers stop coming and the dungeon's management collapses. This dungeon takes Gesell currency as its basis, so problems like those of koban and one-mon coins can be avoided."

So said Scarlet.

"Gesell currency?"

"Master, also called free money, it's a currency whose value falls as time passes. Rice loses value over time, from new rice to old rice to old-old rice, so the currency becomes difficult to hoard away. Of course, you could convert it into koban and store that, but the rice market swings about, so risk comes into it."

"And the thing that smooths that out was the rice futures market, yes?"

"Yes. In a society at an early-modern level, trying to control the rice market only breeds black-market trade, so leaving price adjustment to the market keeps society more stable. On the other hand, if we can use the dungeon to provide what you might call society's safety net, we can set ourselves apart from the surrounding countries."

It's simply that the neighboring countries have no such margin to spare. Even in the Library-City Dungeon the rationed food is a foul liquid fertilizer, but it beats nothing.

"Er, Scarlet-san, this world's currency system is pretty complicated, but couldn't we just issue and manage a currency of our own?"

Gold coin and copper coin each had their own going rate, silver was weighed out by mass, and the iron coin, though its face value was the same one mon as the copper coin, traded at a different rate from it, for, there being no shogunate, it went unregulated.

"Master, first of all, to issue gold coin and the like you need the precious metal itself, and as for paper money, convertible notes require gold to exchange the notes for. 'Fiat paper money,' on the other hand, which guarantees no exchange for gold, rests on the credit of the government, or, were this dungeon to issue it, on the credit of the Library-City Dungeon itself; but since this world has no central bank, paper money is liable to cause trouble, with the issuing government printing it recklessly and inviting chaos, or, in dire cases, the notes turning to wastepaper. So as things stand, paper money of our own would not be accepted."

"I see."

"On a related note, when we scrap electronic devices and the like summoned as library fixtures, with sufficient facilities it's possible to extract gold and copper and mint koban and one-mon coins. Coin we make ourselves circulates normally too, so long as it matches in weight and purity. That said, both gold and copper have many industrial uses, so I wouldn't recommend turning them into coin."

"That's a fair way off, then."

"That said, the thing that could stir up economic trouble is the 'Million-Chōbu Reclamation Plan.' Since the region's productivity will shoot up dramatically in a short span, there's a danger the money supply won't keep pace with the rapid expansion of the economy, and deflation sets in. By that time the Library-City Dungeon's creditworthiness will likely have risen as well, so perhaps we should first issue rice certificates, and only then consider paper money."

"Rice certificates first?"

"Rice being heavy, there's the matter of transport, so the dungeon issues redemption certificates and circulates those instead. Now, the portion already collected as land tax poses no problem, but when we issue rice certificates against next year's harvest, we have to cap them at a quantity we can deliver even in a poor crop, or it turns into a question of credit. Incidentally, part of the reason for rice certificates first is to gauge how far counterfeit-prevention of the paper money is actually feasible."

"True enough. This Library-City Dungeon can obtain comparatively advanced technology, but if there were a dungeon with twenty-second-century technology, there's a chance our paper money would be counterfeited with ease."

"Personal secretary, and not just from the twenty-second century onward, there could be worlds where printing technology has advanced in some peculiar direction. Not every technology develops in proportion to the level of civilization."

"Indeed; compare books from several different worlds and the differences are considerable. I get the sense that worlds that 'didn't go well' somehow tend to lag in technology, too."

"Master, much technology takes enormous development costs to bring into practical use, so constraints from a world's 'economic power' do come into play, after all."

The otherworld closely connected to this dungeon has its backward aspects too, such as battleships still throwing their weight around, or there being no Shinkansen. On the other hand, there are technologies that have advanced in altogether different directions: rockets are by and large solid-fuel, with no liquid-fuel space rockets, yet there exist spaceplanes fitted with detonation rotary engines.