Tourism affects local populations differently in counties across the U.S., but measuring these effects may now be easier thanks to a new tool developed as part of a study by researchers at Penn State. For the study, published in the journal Tourism Economics, the researchers developed a sustainability index to assess how tourism affects counties according to a number of factors that measure the areas' economic, social and environmental well-being. They found that counties relying heavily on tourism varied widely in their ability to keep it from overwhelming local resources, with no destination performing well on every dimension.