December 27, 2013
One of the more useful tools on PCGS CoinFacts is the rarity estimates provided for each regular issue United States coins (and some other series, as well). What is rarity? Rarity is a way of expressing how common or rare a coin can be. Rarity can be absolute (for example, how rare or common is an 1881-S Silver Dollar?), relative (how rare is an 1881-S Silver Dollar relative to an 1893-S Silver Dollar?), or it can relate to condition (how rare is an 1881-S Silver Dollar in MS63 versus MS67).
For many years, collectors relied on official government mintage figures to make decisions about rarity. However, mintage figures can be incorrect for a number of reasons. We know of many instances where coins exist but their mintage figure was never recorded (1870-S Half Dime). Other coins remain unknown despite mintage figures pointing to their existence (1841-O Half Eagle). In many other cases, a high-mintage coin was wiped out by subsequent melting, creating a major rarity (1927-D $20). Often, mintages include coins of two different years, masking the true rarity of both. Thus, rarity ratings and survival estimates give a much better picture of rarity than do mintage figures.
To see how this works, let's take a look at the afore-mentioned 1881-S Silver Dollar. If you're familiar with the Morgan Dollar series, you already know this is a common coin, but let's see what the experts at PCGS have to say about it. To start, type 7130 (the PCGS coin number for an 1881-S Silver Dollar) into the search box on any of the PCGS CoinFacts pages, then scroll down to the "Rarity and Survival Estimates" section (just below the Value-View section).
The "Survival Estimate" column represents an average of one or more experts' opinions as to how many examples survive of a particular coin in three categories: 1) all grades, 2) MS-60 or better, and 3) MS-65 or better). These estimates are based on a variety of sources, including population reports, auction appearances, and personal knowledge. Survival estimates include coins that are raw, certified by PCGS, and certified by other grading services. In the case of the 1881-S Silver Dollar, PCGS experts believe that 1.2 million examples survive in all grades, 600,000 survive in MS-60 or better, and as many as 225,000 survive in MS-65 or better. Simply put, the 1881-S Silver Dollar is a common coin, especially when compared to other coins which are very rare and/or unknown in Uncirculated condition. However, survival estimates are not judgment calls – they are simply statements (or guesses) of reality.
The "Numismatic Rarity" column converts the Survival Estimate for a particular coin into a number from 1 to 10 (with decimal increments) based on the PCGS Rarity Scale. The higher the number, the more rare is the coin. For the 1881-S Silver Dollar, the Numismatic Rarity is 1.0 in all grades, which means it is as common as it could possibly be. In MS-65 or better, the Rarity is 1.8 – still common, but nowhere near as rare as a coin with a Numismatic Rarity of 5.0 or higher.
The "Relative Rarity by Type" column ranks the rarity of this coin with all other coins of this Type. Lower numbers indicate rarer coins. Thus, the 1881-S Silver Dollar is ranked 94th out of 117 Morgan Silver Dollars, making it one of the most common Morgan Dollars. The small arrow in the column heading takes you to a sortable listing of all 117 Morgan Dollars, where you can easily find the rarest and the most common Morgan Dollars, and everything in-between. For example, sorting on the 65+ column in the Rel. Rarity section shows that the most common Morgan Dollars in MS-65 or better are the 1879-S and 1881-S Dollars, and that the rarest is the 1903-S Micro S Dollar. Where is the famous 1893-S Silver Dollar? How about 14th out of 117. Check out this listing for more surprises.
The "Relative Rarity by Series" column ranks the rarity of this coin with all other coins of this series. Lower numbers indicate rarer coins. This column differs when the series is made up of different types. In the case of Morgan Dollars, the type and series numbers are identical because there are no subtypes of the Morgan Silver Dollars. Check out Seated Liberty Half Dollars or Three-Cent Silvers to see how these relationships work.
Rarity estimates, when combined with pricing information and other data, help you chart a roadmap to success as you plan your collecting goals. For instance, if you decide to go after the toughest coins first, rarity estimates provide a checklist of where to start. Get the tough ones out of the way, and you'll have smooth sailing from then on.
Check out the Rarity estimates for your favorite coins on PCGS CoinFacts. You may be surprised at what you'll learn.
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