The common perception that higher immigration rates lead to increased violence may need changing.

Tim Wadsworth, a sociology professor at the University of Colorado at Boulder, completed a study that found immigration may actually be linked to a decline in crime in the United States.

Wadsworth used data from the U.S. Census and Uniform Crime Report on robberies and homicides that occurred from 1989-1991 and 1999-2001 for the study. He concluded that cities with the highest immigration rates in the 1990s experienced lower crime rates.

In selecting crimes to examine, Wadsworth chose robbery and homicide because they are more often reported than other crimes.

In the study, Wadsworth stated that the results he found challenge some common ideas about immigration, namely that immigrants are the cause of crime. Providing evidence for this misconception, he cited a 1993 TIME magazine poll where 59 percent of those surveyed believed immigrants were the cause of increased crime rates.

More recent data suggests the same findings as Wadsworth’s study — that higher immigration does not mean higher violence.

A 2008 study done by the Immigration Policy Center, a Washington-based nonprofit organization, found that nationally, men who are American citizens between the ages of 18 and 39 are five times more likely to be incarcerated than immigrants.

It also showed that although the number of illegal immigrants doubled between 1994 and 2005, violent crime declined by almost 35 percent. During this same time, it was found that cities with a higher number of immigrants had lower crime rates than cities with a lower number of immigrants.

But Alison Efford, an assistant professor of history specializing in immigration, warned against assuming higher immigration was the direct cause of reduced crime.

“As a cautious academic, I would say that correlation and causation are two different things,” Efford said in an email.

She did, however, point out that bias by law enforcers may have helped to create the assumption. She said that in making historical comparisons, it is important to look at how law enforcement works in different contexts.

“Organized crime and crime within ethnic and racial communities has been tackled differently at different times,” Efford said. “American police forces are also infamous for their racial and ethnic biases, but that changes over time too.”

Louise Cainkar, assistant professor of sociology at Marquette, specializes in studying immigration and suggested that bias in law enforcement may influence public opinion on the topic.

“It sounds technically correct without looking at the study, although I think one would have to look at the picture a couple of different ways,” Cainkar said. “In sociology, crime does not increase when immigration increases, though arrests may increase due to racial profiling.”

Caitlin Cervenka, a senior in the College of Arts & Sciences, has a family member who immigrated to the United States from the Czech Republic. She believes the study could change the way people view immigration.

“I think a study like that could bring out things that are ignored about immigrant experience or debunk myths about the morality of the people that enter the United States, “ Cervenka said.

There are some, however, who believe the study is false.

Danielle Kirby, a sophomore in the College of Arts & Sciences, does not believe the study because the crimes of undocumented immigrants may not be reported.

Kirby said she believes illegal immigrants cause more criminal activity and that entering the country illegally is a crime in itself.

“People get smuggled into the country, and people provide fake green cards for them,” she said. “The low crime rate just encourages a new wave of it … It does not lower the crime rate; it just can’t be reported because they’re not documented. “