As California moves toward the legalization of marijuana — next month, voters will decide on Proposition 19, the Regulate, Control and Tax Cannabis Act of 2010 — a key question remains: could the new law produce a whole generation of stoners? Opponents of legalization say, yes, fearing it will lead to a massive increase in pot smoking among youth. But some supporters suggest the opposite: legalizing cannabis could de-glamorize it and ultimately prompt reductions in toking. Who’s right?

That question is surprisingly hard to answer, but two recent research reports offer some potentially useful insight. The first, a Rand Corporation report that led to related testimony before the California legislature on Sept. 21, discusses the effects of price changes and taxation on consumption of drugs. (More on Time.com: What’s in Your Marijuana? Some Pot Doesn’t Rot Your Memory)

A newer report, released Thursday, comes from the new scientist-led International Centre for Science in Drug Policy (ICSDP). It takes a historical look at how U.S. drug policy has affected use, and suggests how to regulate drugs effectively.

One thing the ICSDP report makes clear is that current U.S. drug policy has no effect on marijuana prices or use. While spending on federal drug law enforcement has increased 1,200% and marijuana arrests have risen 150% since 1981, the rate of marijuana use nationwide has bounced around, with no relationship to these efforts.

“No scientific evidence demonstrates an association between the amount of money governments spend on drug law enforcement and rates of drug use,” says Dr. Evan Wood, a professor of medicine at the University of British Columbia, founder of ICSDP and lead author of the report. “And some nations like the U.S., which spend the most have among the highest rates of drug use.” (More on Time.com: 30 Years Since ‘Jimmy’s World’: The Media and Drugs)

Meanwhile, according to national surveys, high school students continue to report that marijuana is universally available, purity has increased and prices have fallen.

The Rand report forecasts how legalization and taxation of marijuana could affect its market price and overall use in California. Although the public tends to view drug users, and addicts in particular, as too irrational and irresponsible to base their behavior on drug prices, research debunks these notions. Studies on legal drugs, such as alcohol and tobacco, for example, show that taxing them and raising prices can often be quite effective in lowering consumption — even among the heaviest users. “After legalization, we expect a large price drop. That’s the biggest take away message from this report,” says Beau Kilmer, co-director of the Rand Drug Policy Research Center and lead author of the report. “We expect the price [of marijuana] to drop at least 80%. There are a couple of other figures out there, ours falls in the middle and you can quibble about the details but there’s a general agreement that the price will drop.”

The trick is to determining how high to set the tax — the price has to be high enough to minimize consumption, but low enough to avoid creating a black market. Kilmer says that the current price for an ounce of good sinsemilla (a type of highly potent marijuana) ranges from $250 to $400. “If that drops down to $50 to $60 an ounce, it would require a really large tax to get [the price back up to that level]. But if the tax is set too high, [we] worry about tax evasion,” he says. (More on Time.com: Is Drug Use Really on the Rise?)

Experts disagree on how much tax evasion occurs under California’s tobacco tax regime, with smokers ordering cigarettes by mail to avoid state taxes, for instance. Some put the figure at 1% to 4%, but the agency that administers the state’s tobacco taxes has said that the rate is more like 15%. Either way, the majority of cigarette taxes do seem to be paid rather than evaded.

Kilmer notes, however, that if Prop 19 passes, each local jurisdiction can set its own tax rate, which could prompt a “race to the bottom,” as localities compete for a piece of the pie. “Regardless of how you feel about Prop 19, how to stop a race to the bottom is going to be important for everyone. No one wins if we end up with a really low tax rate on a really low price,” Kilmer says. To prevent that, he suggests that the state government could withhold certain types of funding to localities that set marijuana taxes under a certain limit.

But let’s say the price of marijuana does end up dropping precipitously. What effect might that have on consumption? Neither report can answer that. “Ultimately, we don’t come up with a conclusion at all on a consumption increase,” Kilmer says, explaining that many factors other than price can affect use. So the report considered what would happen if whole population use increased by 100%.

Interestingly, such use rates have already been experienced in the U.S. The highest rates of marijuana use reported in the U.S. were in the late 1970s and early ’80s, despite harsh drug laws. At the time 60% of high school seniors reported trying marijuana at least once; by comparison, the rate in 2009 was 42%. And what became of Generation X? The kids seem to have turned out all right.

Other countries that have decriminalized or quasi-legalized marijuana — such as Portugal and Holland — also have not seen social disasters because of their drug laws. In fact, they have benefited from reduced enforcement costs and increased access to addiction treatment.

One study did find that rates of marijuana use among Dutch youth increased when “coffee shops” — cafes where selling and smoking of marijuana are permitted — were proliferating and being widely marketed. But, overall, even those elevated rates of use were no higher than U.S. rates under marijuana prohibition. “It wasn’t the decriminalization, it was commercialization that could have caused this,” says Kilmer.

Advertising and commercialization may end up being cause for concern in the U.S. as well, given that medical marijuana ads already seem to be sustaining some newspapers. But, then again, even if Prop 19 passes, marijuana wouldn’t be completely legal — it would still be prohibited under federal drug laws, which could put pressure on the Obama Administration to enforce them (though this Wall Street Journal article suggests that supporting legalization measures could be a boon for Democrats — putting similar measures on other states’ ballots could draw out some key voters on Election Day).

Many questions remain about what will happen if Proposition 19 passes, but the only result I can unequivocally predict is that drug policy debates will finally become less theoretical — and much more interesting.

More on Time.com:

Who’s High? A School Suspends a Student for Bloodshot Eyes

Photos: Cannabis Culture

Video: Taxing Marijuana in California