Spot the difference?

Collectors seem to be just about as tight-fisted regarding their purchases of traditional sets from the U.S. Mint as bullion investors have been in buying one-ounce gold and silver American Eagle coins this year

If we use the bullion coin sales as the yardstick, we see that sales of the one-ounce gold American Eagle is down 46 percent and the silver Eagle is down 23 percent when comparing results of the first nine months of 2012 to the same period in 2011.

There might be any number of reasons for this, but you would not think that collector behavior would virtually mirror bullion buyer behavior in their purchases of popular ongoing annual sets.

But if you look at the regular copper-nickel clad proof set, we see that sales of the 2012 set are down 48 percent compared to 2011. A mitigating factor might be that sales began May 7. But that is still five month’s worth of sales with a group of buyers who tend to act to get their orders in right away.

The silver proof set sales numbers are down a nearly identical amount at 46 percent, but this slightly better performance occurred with during a one month shorter sales window. Collectors started buying these June 4.

The clad 5-quarter proof set has numbers that are 24 percent lower. Sales began Jan. 17, 2012.

Buyers of the silver 5-quarter set seem more committed as this decline is just 12 percent. Sales of these began Jan. 10, 2012.

Buyers of 4-coin Presidential dollar proof sets are 29 percent fewer. Sales began April 24, 2012.

Any one statistic might be influenced by some peculiar factor that does not affect any other, but the orders of magnitude of all of these declines being so similar to bullion results raises the question:

Why are collectors moving in lockstep with bullion buyers? Factors like stressed incomes, etc., were just as true in 2011 if not even more so.

Aren’t we supposed to be motivated by set building, or have bullion headlines now become our guiding buying signal?

Buzz blogger Dave Harper is editor of the weekly newspaper "Numismatic News."