The Marcellus Shale boom does not appear to be driving up crime rates in Pennsylvania, but more research is needed to gauge the actual impact, according to a Pennsylvania State University report.

Comparing the arrest rates and the number of calls to the Pennsylvania State Police in the most active Marcellus counties, the report from the Justice Center for Research at Penn State found “no consistent increases” between the years 2006-2007 — before significant shale development began — and 2008-2010 — the first years of the boom. But while those rates stayed roughly the same in Marcellus country over those five years, they dropped in rural counties without drilling, the report found.

“In the three years since the Marcellus break-out period in 2008, there was a difference in the trends of state police incidents in Marcellus and non-Marcellus drilling areas, but the difference isn’t so striking that we can say, ‘there’s definitely something here,'” said Lindsay Kowalski, a research associate in the Justice Center for Research. “More time needs to elapse before we can identify strong trends.”

Kowalski and Gary Zajac, managing director at the Justice Center for Research, wrote the report.

The report followed anecdotes from shale country about crime rates rising alongside drilling rates.

The researchers tracked crime statistics in seven development-heavy counties that account for a majority of the drilling done to date in the state: Bradford, Susquehanna, Tioga and Lycoming counties in northeastern Pennsylvania and Fayette, Greene and Washington counties in southwestern Pennsylvania. They found increases, decreases and steady figures in crime rates in all seven counties, but the combined statistics showed crime decreasing in 2008 and 2009 and increasing in 2010.

But crime rates in non-Marcellus counties have declined every years since 2007.

The report also found that the types of arrests also remained roughly the same between 2006-2007 and 2008-2010, but that arrests for driving under the influence increased somewhat sharply in 2010.

The researchers said the findings must be considered in light of the short time frame considered so far, and the fact that they did not have access to local police records. While the Pennsylvania State Police handle much of the incidents in rural Pennsylvania, they don’t handle crime at the municipal level. The researchers also noted that they focused on arrest rates, and not all reported crimes end in an arrest.

Finally, the researchers said they need to find a closer match to the seven Marcellus counties among non-Marcellus counties in order to get a more “rigorous” comparison of crime rates from each.

The Justice Center for Research hopes to combine its research with previous work done by the Pennsylvania Commission of Sentencing and the Administration Office of the Pennsylvania Courts.