Arts proponents frequently argue that the arts have a positive impact on the economy, yet this assertion is not … supported by satisfactory statistical testing. Using the U.S. Gross Domestic Product (GDP) and National Arts Index (NAI), this … study seeks to verify the contention that arts activities enhance economic growth. The test results signify, at the national …

understand how to manage these services it is essential to understand how ecological communities are organized and how to measure …, stabilize soils, purify water, and in general provide a nearly endless list of services essential to life as we know it. To … the biological diversity they contain. Ecological communities are comprised of many species, which are in turn made up of …