Economic growth around the world: rich economies and poor economies are dynamic and can easily change to become poor economies and rich economies. The stock of equipment and structures that are available to a worker to produce goods and services or a worker"s physical capital, can alter a worker"s productivity. The knowledge and skills that are available to a worker such as education, training, and experience, or a worker"s human capital, can alter a worker"s productivity. The inputs provided by nature to the production of goods and services, such as land, mineral deposits, and other natural resources can alter an economy"s productivity. The societal understanding of the most efficient methods of producing goods and services or a society"s technological knowledge can alter an economy"s productivity. Traditionally, capital is affected by a property wherein the addition of an extra unit of input decreases in benefit as the quantity of the input increases, also known as the property of diminishing returns.