These aren't activities that one needs it to be quickly accessible, either.
Trading vis would happen two ways. The first way would be via letters of exchange to be delivered by Redcap, thee would be more like trades, than sales. The second way would to have the vis available at tribunal for sales, charging a premium for the vis, since it is here and available, rather to be delivered later.
healing might well be something you need to have handy in an emergency, as to trading, if you have to have it close by and you have already invested it in jewelry, why not? Technically I don't have to have a knife "at hand" to cut carpet, wood, or any other thing I would use it as a tool for, yet people do carry work knives on their belts.
So yeah there is the first thought, "Ha! what a silly notion about money". Then there is the second thought, "Wait people actually thought this OMG!" Now here is the final realization "OMFG they where actually kind of right!".
If you actually think about in the medieval time period saving money IS financially irresponsible. It's the Paradox of Thrift. Stowing money away might be good for an individual but it is essentially hoarding a limited resource. If everyone saves there money an economy will lose it's fluidity and dry up. Modern economists go back and forth on if the paradox holds true now a days because saved money isn't really removed from the market. It goes into interest bearing accounts, or secure bonds or gets invested in stocks basically allowing other people to spend it and keep it circulating.
In the 13th century saving money would likely remain a selfish choice, akin to hoarding food. There is really no form of secure investment available, No real options for effective capitalization and even lending on interest is generally seen as verboten. So saving money usually amounts to stowing it under a mattress. Now if my grandmother was right that isn't just generally bad for the economy, but a pretty risky personal choice.
Actually there were investment options, but they were pretty sneaky. For example the concept of an annuity was a way to turn a loan around to avoid charges of usury- You pay me up front for a series of payments made over time- there is no mention made of an interest rate, and I am not borrowing money from you, I am selling you an annuity, but it is pretty much the same thing. But it was also far from common. Of course the example in the book was someone reinvesting in their business instead of enjoying the fruits of their labor being wrong, which makes even less sense from a modern perspective, but made sense to the medieval perspective because if you were making money from the labor of others that was obviously wrong, since they should get to enjoy the fruits of their own labors, so putting resources into expanding your business and employing more people is just tightening your grip over more people and extracting your wealth from their work...
Merchants and the wealthy in the middle ages always tried to secure their livelihood at old age, or that of their families in case they did not return from a journey. This led to early instances of life insurance business run by prestigious monasteries.
We happen to have documents from the abbey of St. Emmeram in Regensburg ( en.wikipedia.org/wiki/St._Emmeram%27s_Abbey ), dating to the beginning of the 11th (!) century, which stipulate lifelong annuities or a pension to surviving dependents as recompense for a donation to the abbey (see Die Traditionen des Hochstifts Regensburg und des Klosters Sankt Emmeram, editor: J. Wittmann, in Quellen und Erörterungen zur bayerischen Geschichte Neue Folge 8 ).
Money stuffed eternally under a mattress doesn't do anybody any good, but that's not what I'm talking about. Competition is great for the economy and better-quality goods are good for everyone, so saving money to invest is good, both for the individual and in general, at least economically speaking. And while going over the top with it can understandably be looked down on, having at least some money saved is good in a place like medieval Europe, doubly so in Mythic Europe, because with no savings, any financial disaster (theft, earthquake, monster attack, even just money wasted on an investment that didn't pan out) could take a person, family, or entire business out of the customer base temporarily or permanently. This is practically unnoticeable with big businesses, but big business is pretty rare at this point, so total economic collapse in a town could totally happen if one business or business group (say, the major crafting guild in a town) suddenly stops providing their 50% or more of wood/quarry/base metal/whatever purchases.
Thomas piketty mentions that debts against the income from land were generally not considered urusurous...which seems like a big loophole to me. I agree with your more general points, here. Annunities are an easy way to get interest payments. They also did some things where you repaid in a currency that was worth more than the loaning currency.
Is it, in C13th, though? Competition is good for the consumer, and in the Middle Ages that generally means the already wealthy - subsistence peasants aren't going to get more and better if there is competition in their economy (certain things like querning rights aside). Hence the anti-compeitive practices of guilds: they are there to prevent a race to the bottom where the lifestyles of the guild members are hollowed out so the nobility can have even nicer things cheaper.
It is good...in the sense that it allows people to transform their labour into productive capital, but I'd note that doesn't happen a lot in the rural economy. They turn their labour into capital in other ways...for example by directly improving land. I'm not saying it doesn't happen, but I am saying that the setting is more like African microfinance than modern American lending.
The belief is basically that saving is wrong, because spending creates jobs. Money is not, of itself, fruitful.
Now, how do you deal with shocks? Basically as a noble, you sell something, you get another rich noble to bail you out, through marriage, court offices (leading to incessant military service and needless border wars, btw) or you get credit on another source of income,
Or you just lower that standard of living of your peasants...which is a popular choice.
The feudal economy is really not stable. Well, it is stable in the way that subsistence agriculture is stable: it is stable because the population fluctuations are less terrible to talk about than experience.
I've read some of these, and I'd like to note that they don't just say how the person would be houses and what food they would get: they are also specifically designed to maintain a level of dignity in age that the children of he annuity holder can't cut into. There's an incessant drumbeat of sitting by the fie in some of these that I never really understood until it struck me that a person with a seat by the fire is a person with status, and that it was about the person keeping some of their scial cachet now that they had lost their financial power.
Actually to my understanding the thirteenth century is generally a cash poor economy. In that situation stuffing a significant amount of money under a matress for any amount of time would be harmful to the economy.
This begs the question, how do you expect to invest this saved capitol? What resource will this influx of money provide to produce better quality goods? Unlike our industrial soicity most tooling used by trades is produced by the tradesmen themselves. So there is little capitol investment in facilities that doesn't require a commiserate increase in manpower. So you invest in labor? But Unemployment in the modern sense is not really present. Unfortunately there is no ready supply of skilled labor looking for work and little reserve of unskilled labor. Paying people to work longer hours doesn't even work well. Never mind the moral aspect mentioned in the game. People's non profesional life of family and community involves more labor then most modern people put into there careers.
Again you run into the problem of hard currency being a limited resource. Saving a large enouph amount of cash to bail a community out of such a disaster could very well be the cause of said disaster.
Jewelry for instance has long been used as an asset one could own and use but also easily sell for capital. It doesn't tie up hard currency on display around your neck or in your safe back home. So it's a good place to park funds till you need them. For emergencies or a dowry or funding a crusade.
Preserving social standing for themselves or their heirs is certainly a motivation, which also is very visible in contracts about retirement to a monastery.
But the 11th century documents of St. Emmeram speak of regular payments of money to the donor (e. g. document #265) or money payments to his heirs (e. g. document #327). These documents are easily accessible in German as part of the book of Hartmut Boockmann Das Mittelalter (C. H. Beck 1988) - see amazon.de/Das-Mittelalter-Le ... 3406333885 . I am not aware of translations of this book, though.
You don't invest capitol or hide cash under your mattress, silly. There's this ethereal timespace goop called "labor points" that represents a combination of one part cash, one part fruits of your labor (time and resources), one part non-cash credit, and two parts miscellaneous. That is what you invest. Kind of hard to put under a mattress though, but it's also pretty hard to steal so no worries there.
Recently had a discussion about investing in a business in another thread. A certain amount of cash is worth so many labor points when invested into a business. So, yes, you can invest in a business and gain labor points. It becomes difficult to take those labor points out of the business, however.