Although the potency of cannabis has increased in almost all European countries between 2006 and 2016substantial differences persist between countries, with significant consequences for public health. Possible explanations for variations in the cannabis market across Europe include tastes (demand side) and differences in price
due to repression (supply side).
One of the characteristics of the illicit drug market is the unexplained variability of product characteristics between countries. For example, the markets are balanced at a surprisingly different purity. As we have seen recently with the Madrid resin.
For hard drugs the purity index is important in the face of the risk of overdose
According to the doctor Tom Freeman active member of the British Association of Psychopharmacology no study provides insight into what determines the purity at which a market equilibrates, but purity can be important for the risks of overdose. In the case of cannabis there is no overdose ....
Freeman bring new observations to this puzzle of variable equilibrium on the national markets. They present data on the potency of cannabis [measured by the percentage of tetrahydrocannabinol (THC)] in 21 European countries during the 2006-16 period.
If we put aside the Netherlands, with their quasi-legal market for cannabis and their unchanging power of 15%, the range of 2016 is about 3-15%, while in 2006 it was about 0,5-10%. Similar trends can be observed for cannabis resin. There is little evidence of convergence or harmonization between markets.
What could explain these persistent differences in the potency of cannabis?
Three assumptions: one on the demand side and two on the supply side.
Divergent national preferences for various reasons, the alcohol markets have shown persistent differences in the shares of alcohol consumption of wine, spirits and beer. Although there is some evidence of convergence in Europe, at least in part because of more uniform tax and regulatory policies, transnational differences in these shares remain significant.
In some countries, consumers prefer higher power, or at least have become accustomed to strong cannabis. During 10 last years, the ranking of countries has changed
marked. For example, Croatia has gone from the penultimate power (in THC) lowest in 2006 to sixth in 2016. France always number one. Although variation in taste certainly plays a role, it is not compatible with consumer preferences.
Variation in the application of the law : The power of cannabis is a consequence of the way it is produced. Indoor growing, which is often associated with more potent cannabis, reduces the risk of detection. For example, more intense enforcement or harsher sentences following a conviction may favor smaller growing areas and greater power. High power can therefore be the result of more intense application or harsher penalties.
Variation in the cost of internal productions Prices of indoor crops, especially labor, energy and land, vary by country. Where labor is expensive and land and electricity are cheap, farmers can choose to grow cannabis at low power. Thus, regardless of the application of the law, power variations may reflect economic differences between countries.
There is no doubt that other studies can invoke other factors that plausibly influence the average potency of cannabis. As for purity in the markets of cocaine and heroin, the power of cannabis is a producer's decision, which partly reflects the taste of the customer. Variation in potency is probably important for public health, as Freeman and his associates point out, because user titration is flawed; those who consume very high potency cannabis may consume more THC. Thus, it would be useful to study the question.