On Ebay's Imperial Roman Coin Market And History

Absolutely, first off, welcome. Quite a splash I think you're making with your initial contribution!

Do you intend that this research will form the basis for a published monograph? There are members here who can probably put you in touch with the right people to have that accomplished.

@Lucky Cuss

I would love to publish the final product in some official capacity, if there are members in the community that can help with that I would really like to get in touch with them if only for the professional input.


@jskirwin

I'm using ebay's API to check the front page of ended listings under the "Imperial Roman Coins" category every N minutes and storing any new updates.

For the different aspects of the coin (ruler, denomination, etc..) It's a bit trickier:

I run a search with ebay's API with one of those selected (i.e, "Show all ended listings where Ruler = Augustus") and enrich the previously collected data with the new information.

ebay are quite strict on their API limits and I do not intend to overuse their limits by "hacky" ways, so the data collection takes a LONG time. as mentioned in the article, the data collector was running for more than 7 months.

The Math behind it is for now quite simple, as it's really the first first conclusions to draw from the data set, so it's a few scripts that produce the charts.

I sidelined a bit at some point when I got interested in machine learning and was able to produce this project:
https://github.com/dzautner/roman-c...fication-cnn

That will deduct the ruler based on the description of the coin with ~95% accuracy. It doesn't sound like a difficult task as the ruler will usually be in the title, but it is also able to tag titles such as "FL IVL CONSTANTIUS NOB C - GLORIA EXERCITVS 334-335 AD" correctly (Constantine II) which is really nice.

Very interesting article!

Some number of years ago, some members posted a similar tabulation of completed auctions (from major auction houses, IIRC) broken down by the 207 emperors, Caesars, wives, usurpers, and family members who issued coins in their name or image from the beginning of the Principate in 27 BC to the coinage reform of Anastasius in the 490s. It would be quite interesting to see how the two compare; I remember that Constantine was at the top by a wide margin, and I was surprised to see Nero near the top as well.

E: here is the thread:
http://goccf.com/t/127458&SearchTerms=207

dzautner
Do you collect Roman Imperial coins?
We could use a guy like you in the hobby.

As I have unfortunately learned, listing Roman coins as a $0.99 auction is risky business unless you are a well-established seller with a lot of followers. I have been on both sides of being "taken to the cleaners", if you will. Sellers who don't like to risk it might start coins for a higher starting price, which results in less competition and less sense of urgency.

And yes, a lot of sellers like to ask outrageous prices - "highrating_lowprice" is one who lists dozens of $50-250 coins for $500-5,000 over and over again until they sell. And they do sell - so he keeps doing it!

The numbers you are "crunching" are impressive, but I am finding them a bit confusing. You report that in the past 7 months there have been over 250,000 listings, of which 19.6% sold.

You also report an average of 194 new listings per day. That number of daily new listings only gives us 35,405 new listings in 6 months. Since you do not say what the population was at the start of your data collection, I cannot tell the significance of these numbers.

I am also confused by the purpose of excluding transactions for coins sold from the New World. Since the stats focus on seller location, are you supposing that coins in "Old World" countries are new finds? If so, I think that needs to be reconsidered, since some percentage of the material in the hands of those sellers represents material that has been circulating in the market place for generations. While I would agree that 100% of the material in the "New World" is recirculated market, how do we differentiate old market and new excavation among the material being sold in "Old World" countries? Or is that not the point of mentioning the distinction in geography? If not, what IS the point?

There is great merit to having a breakdown by locale, in trying to assess the kind of market we have for specific material in different places. But apart from telling us what material is popular in various places, I don't yet see what we learn from making the "Old World" "New World" distinction.

Are you using all 41 country-specific ebay sites or only American ebay (.com)? If you are only scraping data from ebay.com, the results will naturally skew toward the US as both importer and exporter.

I. currencies
Thank you for asking. First a couple of observations. One of the sellers I have worked with several times, frequently offers the same material simultaneously as separate lots based on the currency for payment. I have seen simultaneous listings of a coin in dollars, euros, Canadian dollars, and British Pounds. In more than a few cases, the cost of the coin after conversion to dollars can be cheaper than it is if bought with dollars outright. So it pays to shop around between the currencies.

II. specialties
when I am looking for coins of a particular figure, such as Julia Domna, I do various kinds of searches in ebay.com for her material. However, I am ignorant of what might be offered from the international vendors who do not sell through ebay.com. Nor am I inclined to search each international "version" of ebay for listings, unless there is a high probability o finding something the .com venue is not listing. I don't know how to sort all that out, but it may be there is an algorithm that will group offerings from ALL ebay sites and give me the option to search as many as have relevant new offerings day by day.