In the field of economics, the concept of a market economy is largely considered a modern phenomenon. Influential economists such as Karl Marx and Max Weber, for example, argued that although markets existed in antiquity, economies in which structures of production and distribution responded to the laws of supply and demand developed only as recently as the 19th century. A recent study by an international team of researchers, including Adam Izdebski of the Max Planck Institute for the Science of Human History, uses palynology—the study of pollen remains extracted from cored sediments—to challenge this belief and provide evidence for an integrated market economy existing in ancient Greece.