Charles D. Phillips, Texas A&M University School of Public Health, published a paper in 2015 entitled “Concealed Handgun Licensing and Crime in Four States.” He and his research team concluded that concealed handgun licensing had no beneficial effect on crime, and that the main driving force behind more people obtaining a license was the presence of federally licensed firearms dealers. However, there are a number of errors, assumptions, and miscalculations in his research that justify revisiting the question of the relationship between concealed carry laws and crime.
This is a paper written and published by Howard Nemerov. You can obtain the paper here.
The TSRA Sportsman recently published Howard’s article, but unfortunately the printing had numerous errors. I asked Howard about it and he gave me the above link to the full paper.