Conservationists have long assumed that when professional collectors, the people who can quickly and efficiently do the most damage, quit the field they inevitably leave enough specimens available for conservationists to save, and hopefully, enough to help grow the population to pre-exploitation levels.
Or if the pressure of the hunters, helped or caused the species rarity, the species has received a temporary pardon, providing conservationists and scientists some additional time to think about the problem, to study it, and to develop the right recovery plan.
I believe the concept of "commercial extinction" is meaningless.
The assumption that drives the concept of "commercial extinction," is that when the professionals leave the field, to find a more profitable resource to exploit, no one replaces them. Unfortunately in underdeveloped countries this is not true and probably never was.
When a commercial collector leaves the field they are immediately replaced by a new set of collectors. Collectors who have all the time in the world to invest, collectors who will go to great lengths and take great risks to find or catch the plant or animal -- especially if the demand for the species has increased the price.
Some of these collectors are usually "in-transit" or refugees. They could have come from within the same or another country. The collectors also consist of people who live in the area and are so poor they barely survive.
Using the same formulae used to determine commercial extinction, you can also prove the term's own invalidity. If the collector is a refuge, they spend most of their time sitting in refugee camps. Time is the only thing they have to invest.
A starving local farmer who can barely feed their family can be easily pushed to take great risks to supplement their incomes. Anyone, in any country, would.
So with all these new reserves of time and risk to invest, versus the potential return -- it is almost guaranteed that these new collectors will be out in the field until they are absolutely sure they've found the last one.
How much of a return can these collectors expect? Reportedly the market for the Asian box turtle Cuora trifasciata is so lucrative that a collector can earn up to $375.00 U.S. for a specimen up to 700 grams. A collector in Vietnam can earn up to $1,000US/kg in a country where the average yearly income is $200 US (Shi and Parham, 2001).
Conclusion? Once a market has been established for a plant or an animal, conservationists should not pause to act. "Commercial extinction" does not exist, it doesn't provide a pause on the organisms's march to extinction, and so does not give anyone more time to act, or create peer reviewed, scientific sound "recovery plans."
Or as John Muir stated, ""If it's a race between the market and nature, the market always wins."
Shi, H. and J.F. Parham. 2001. Preliminary Observations of a Large Turtle Farm in Hainan Province, People’s Republic of China. TTN 3: 4-6.