An August report from the Brookings Institution found that industrial robots are largely concentrated in midwestern and southern states, where the automotive industry dominates.

Specifically, more than half of the 233,305 industrial robots in the U.S. are clustered in 10 states in these regions with Michigan deploying 12% of the nation’s total. Ohio hosts 8.7%, and Indiana houses 8.3%. Only 13% of all U.S. industrial robots are located in the western parts of the country.

“This clustering follows logically from the fact that the auto industry—highly concentrated in the Midwest and upper South—currently employs nearly half of all industrial robots in use,” author Mark Muro wrote in his “Where the Robots Are” report.

When looking closer into the states, the data shows industrial robots are also concentrated around cities heavily involved in the automotive industry, such as Detroit, which has more than 15,000 industrial robots in use. Toledo, Ohio; Grand Rapids, Mich; Louisville and Nashville also host a large number of industrial robots and saw their number of robots triple after the auto boom between 2010 and 2015.

“Regardless of whether these robot densities are meaningfully limiting aggregate employment in these metros … there is no doubt that robotics are playing a substantial role in shaping the dynamics of many, though by no means all, local economies,” Muro said.

Robotics are also centered around areas focused on manufacturing, including the electronics, rubber and plastics industries. “Their incidence reflects the nature and geography of the nation’s highly automated advanced manufacturing sector,” Muro said.

Drawing from the concentration, he notes that automation will not have the same effect everywhere, and places will adopt the technology based on “the workings of global value chains as they are shaped by the local industry mix, skills, location.”

In his research, Muro used data on the installation of robots and automation systems in American industries and metropolitan areas from the International Federation for Robotics.

This report was part of a larger Brookings effort to study where the effects of automation might be the most disruptive based on estimates of the susceptibility of certain occupations to replacement by robots.