Researchers who look at four states where pot is legal find no evidence of negative outcomes.

FALL RIVER, Mass. — We are either facing the end of the world or utopia, depending on whom you ask.

Either way, both pro and con forces say life will change based on the vote for referendum question four, which asks if Massachusetts should legalize the recreational use of marijuana.

Proponents say legal marijuana will raise tax revenue, reduce crime, stimulate the economy and improve public health.

Opponents say legal marijuana will increase the use of alcohol and other drugs, increase crime, cause traffic accidents and cause teenagers to skip school.

But Colorado, Oregon, Washington and Alaska say don’t worry about it. No matter which way the vote goes, nothing much will change, according to Harvard professor Jeffrey Miron.

Miron is a senior lecturer on economics and a senior fellow at the Cato Institute, the libertarian think tank.

Miron joined researchers Angela Dills and Sietse Goffard to write a paper for the Cato Institute in September, offering a statistical analysis of the effect of referenda in Colorado, Oregon, Washington and Alaska that legalized the recreational use of marijuana.

Massachusetts will be one of 11 states, including Maine, considering that question on election day.

“Based on the four states, we didn’t find any changes or any of the outcomes that have been projected,” Miron said. “Any changes were very minor.

“What we found was evidence of increased tax revenue. The four states have taken in a modest amount of increased revenue as a result of the change.”

The paper looks at the legal history of marijuana laws – it was legal through the United States until 1913, when California became the first state to prohibit it. The federal government first got involved in 1937, when it imposed a prohibitively high tax on marijuana. Possession of marijuana did not become a federal crime until the 1950s.

Washington, Oregon and Alaska made medical marijuana legal in 1998. Colorado made recreational marijuana legal in 2012. (In Massachusetts, medical marijuana is legal. Possession of less than an ounce of marijuana is a civil rather than criminal offense.)

Miron and company looked at a decade of statistics from Colorado, Oregon, Washington and Alaska. In those studies, both marijuana and alcohol use remained steady, both before and after legalization. Marijuana prices remained stable and suicide rates showed no appreciable increase or decrease.

Admissions to emergency rooms in Colorado for treatment of alcohol or marijuana both declined slightly after marijuana was made legal. In Washington, ER admissions continued a decline that started in 2008. The crime rate and the violent crime rate remained stable in both Denver and Seattle. There was no appreciable change in the rate of traffic accidents or traffic fatalities after legalization in any of the states that had sufficient post legalization data, according to the paper.

In schools, suspensions remained stable as did standardized test scores.

Home prices and unemployment rates followed national trends in all four states. So did state spending on corrections and state police expenditures.

The biggest change has been in state revenue: All four states collected steadily increasing tax revenue from legal marijuana sellers.

“Our conclusion is that state marijuana legalizations have had minimal effect on marijuana use and related outcomes,” the paper states.

The authors note that there are only limited statistics available and that, over time, the results could change.

“On the basis of available data, however, we find little support for the stronger claims made by either opponents or advocates of legalization. The absence of significant adverse consequences is especially striking given the sometimes dire predictions made by legalization opponents.”