The police foundation conducted the classic kansas city preventive patrol experiment, which showed that increasing or decreasing the level of routine preventive patrol—the -backbone of police work—had on crime, fear of crime, or citizen -satisfaction with police services.

I believe the blank is supposed to be "any effect".

Americans often speak of their country as one of several large regions.  these regions are cultural units rather than governmental units --  formed by history and geography and shaped by the economics, literature and folkways that all the parts of a region share. what makes one region different from another? a region's multicultural heritage as well as distinct demographic characteristics like age and occupation make regions different and special. within several regions, language is used differently and there are strong dialects. there are also differences in outlook and attitude based on geography.