The Purchasing Managers' Index (PMI) is a survey-based measure of business activity in the manufacturing and services sectors. It asks respondents about changes in key business variables from the previous month. A PMI above 50 indicates expansion, while a figure below 50 indicates contraction. The PMI provides an early indicator of economic activity and is watched closely by central banks and financial markets. Recent PMI figures in India have declined due to reforms like demonetization and GST implementation, but are expected to gradually recover as businesses adapt to the new systems.