The Purchasing Managers’ Index (PMI)

The Purchasing Managers’ Index (PMI) is a critical economic indicator used to gauge the health of the manufacturing and service sectors. It represents the economic trends and conditions from the perspective of purchasing managers across various industries.

What is the PMI?

The PMI is a barometer of economic trends in the manufacturing and service sectors. It consolidates the perspectives of purchasing managers who oversee supply chains in their respective companies, offering a snapshot of whether the market conditions are expanding, stagnant, or contracting. PMI surveys cover new orders, inventory levels, production, supplier deliveries, and employment, with each component weighted equally.

Example: If 55% of purchasing managers report that new orders are increasing, 35% report no change, and 10% report a decrease, the PMI would signal economic expansion, typically resulting in a PMI above 50.

How the PMI Works

The PMI is calculated monthly by the Institute for Supply Management (ISM) based on surveys sent to executives at over 400 companies in 19 industries. These industries are selected based on their contribution to the GDP. The PMI ranges from 0 to 100, where a reading above 50 indicates expansion compared to the previous month, below 50 indicates contraction, and a reading of 50 signals no change.

The PMI formula is:

PMI = (P1 * 1) + (P2 * 0.5) + (P3 * 0)


  • P1 = percentage of respondents reporting improvement
  • P2 = percentage of respondents reporting no change
  • P3 = percentage of respondents reporting deterioration

Example: If 70% of respondents see improvement, 20% see no change, and 10% see deterioration, the PMI would be (70 * 1) + (20 * 0.5) + (10 * 0) = 80, indicating robust economic expansion.

The Purchasing Managers' Index (PMI)

Economic Impact of PMI

PMI data informs decisions across various managerial roles. For instance, in the automotive industry, a manufacturer might use PMI data to forecast demand and make decisions on production schedules, raw material purchases, and labor requirements.

Example: An automaker noticing a PMI above 60, indicating strong growth, may decide to increase production volumes and purchase more raw materials like steel and plastics to meet expected higher demand.

Suppliers also use PMI to adjust their operations and pricing strategies. For example, a parts supplier tracking a rising PMI may anticipate increased orders from manufacturers and may adjust their production plans and pricing accordingly.

Example: If a parts supplier observes a PMI rise to 65, suggesting strong demand, they might increase production and raise prices to reflect higher costs and greater demand from their clients.

Investors utilize PMI as a leading economic indicator. Changes in PMI often precede shifts in broader economic metrics such as GDP growth, industrial output, and employment levels, making it a valuable tool for making informed investment decisions.

Example: An investor noting a consistent PMI rise may predict economic growth and decide to invest in equities within the manufacturing sector, anticipating higher corporate earnings and stock price appreciation.

How to Interpret PMI for Strategic Decisions

Businesses use PMI data for strategic planning and operational adjustments. For instance, a company might revise its budget forecasts, adjust inventory levels, or alter workforce management based on PMI insights.

Example: A retail chain noticing a PMI decline might reduce inventory orders and delay expansion plans, anticipating lower consumer demand in the near future.

PMI data is also essential for economic policymakers and analysts. Governments and central banks monitor PMI trends to make policy decisions that support economic stability and growth.

Example: A central bank observing a declining PMI might consider lowering interest rates to stimulate economic activity.


In conclusion, the PMI is an indispensable tool for business leaders, investors, and policymakers, providing early insights into economic conditions. By understanding and leveraging PMI data, stakeholders can make more informed decisions, anticipate market trends, and strategically navigate the economic landscape.