Predict Inflation With the Producer Price Index (PPI)

Inflation, or the rate of change in prices for a basket of goods and services, is one of the most anticipated indicators to gauge the overall health of an economy.

For investors, inflation is an extremely useful measure, since it can be used as a leading indicator to speculate on the future direction of interest rates. Typically, interest rates have a negative correlation with market returns.?Learn how to predict rising or falling inflation using the producer price index (PPI), which tracks the prices that producers pay.

Key Takeaways

  • The producer price index (PPI) measures inflation from the perspective of costs to industry or producers of products.
  • Because it measures price changes before they reach consumers, some people see it as an earlier predictor of inflation than the CPI.
  • PPI data is segmented into three main areas of classification, with the core PPI the most-watched.

Why Inflation Matters

A low and stable rate of inflation is most often found in healthy growing economies with effective monetary policies.

On the other hand, runaway inflationary environments significantly reduce the purchasing power of individuals' savings, while deflation is indicative of an economic slowdown. Economists and policymakers work closely with central banks to coordinate optimal open market operations and monetary policy adjustments that promote a stable long-term rate of inflation. 

When inflation is high, central banks increase interest rates in order to restrict economic growth and the continuous demand for funds. Likewise, deflation, or periods of decreasing prices, will often force an increase in the money supply as a government attempts to stimulate the economy.

What Is the Producer Price Index (PPI)?

The Consumer Price Index  (CPI) is often the most frequently cited measure of inflation. This metric measures the price change of a basket of goods and services from the perspective of the consumer.

However, the producer price index (PPI), often overlooked, can also be utilized to assess the rate of change in prices. The PPI is a wholesale measure of inflation. According to the Bureau of Labor Statistics (BLS), the government body that collects PPI data and releases it on a monthly basis, the PPI "measures the average change over time in the selling prices received by domestic producers for their output."

The PPI is somewhat similar to the CPI with the exception that it looks at rising prices from the perspective of the producer rather than the consumer. While the CPI looks at final prices realized by consumers, the PPI takes one step back and determines the change in output prices faced by producers. The discrepancies between the two prices are based on factors such as sales taxes and markups as products move through the various stages of the supply chain.

Despite the two measures being constructed differently, historically there has been a close correlation between changes in CPI and PPI.

How PPI Is Measured

There are three basic measures of PPI that are based on the various stages of processing, providing an index on crude, intermediate, and finished goods.

Crude goods, measured by the PPI Commodity Index, reflect the changing costs of input materials such as iron ore, aluminum base scrap, soybeans, and wheat. The PPI stage of processing tracks the price changes of goods in the intermediary stages of production. Included in this index are products such as refined sugars, leather, paper, and basic chemicals.

Core PPI refers to the index of finished goods and is generally what economists refer to when the producer price index is referenced. Footwear, soap, tires, and furniture are among the items included in core PPI.

PPI can also be broken down into general categories of input and output measures that reflect the rate of change in prices for which consumers buy and sell their products, respectively.

When core PPI is calculated, volatile items such as energy and food prices are excluded from the core calculation. Although these omissions reduce the overall accuracy of the index, their prices are heavily influenced by temporary supply and demand imbalances that would make the index difficult to compare on a long-term basis. Luckily, the?BLS?tracks the price changes for many of these missing components, so interested analysts can recalculate the index values to include food and energy inputs.

Once the price changes have been compared to those faced in 1982, which serves as the base year for the index (value = 100), the overall value of the PPI is calculated using a weighted average. The weights are determined by the relative importance of the components in terms of their share of total national output. For example, plastic bottles and residential lubricants have a much greater associated weight than candles or umbrellas. The cumulative weight of the thousands of items included in the "basket" sums up to 100%. 

In January 2011, the?BLS?began experimenting with improvements to the stage-of-processing index. After initially focusing only on the price changes of intermediate processed and unprocessed goods, the analysis began to track the escalating costs of services and construction activities as well.

Why PPI Is Important

Inflation is probably the second-most-watched indicator after unemployment data, as it helps investors deduce the future direction of monetary policy. The core PPI can serve multiple roles in improving investment-making decisions because it can serve as a leading indicator for CPI. When producers are faced with input inflation, those rising costs are passed along to the retailers and eventually to the consumer.

Furthermore, PPI presents the inflation picture from a different perspective than CPI. Although changes in consumer prices are important for consumers, tracking PPI allows one to determine the cause of the changes in CPI. If, for example, CPI increases at a much faster rate than PPI, such a situation could indicate that factors other than inflation may be causing retailers to increase their prices. However, if CPI and PPI increase in tandem, retailers may be simply attempting to maintain their operating margins.

Economists can also forecast the future movement of the finished goods index by monitoring the intermediate index, and the direction of the intermediate index can be determined by analyzing the crude index.

Essentially, the data obtained from monitoring the downhill indicators, those focused on raw materials, can be used to forecast the uphill core indicators.

The PPI of finished goods provides a sense of the expected CPI movement.

When companies experience higher input costs, those costs are ultimately passed on to the subsequent buyers in the distribution network. These firms will then charge higher prices for final products that are delivered to retail locations. Although firms throughout the supply chain will typically hedge their input costs, higher prices will eventually be realized once the fixed price contracts expire.

Is PPI a Good Indicator of Inflation?

PPI can be a good pre-indicator of inflation, because it measures the costs to produce consumer goods. When costs rise for manufacturers and producers, retail prices tend to go up as well.

What Is the Difference Between CPI and PPI?

CPI, or consumer price index, measures the prices that consumers pay and therefore also accounts for taxes and other additional costs. PPI, on the other hand, only measures the cost to the producer, and does not include taxes or imports.

Is PPI Usually Higher than CPI?

Yes, PPI is often higher than CPI. This is partially because the PPI measures a different "basket" of costs than the CPI. It's also partly due to the fact that when business's costs rise, they don't always immediately pass on that cost to the consumer. Plus, PPI mostly measures goods, while CPI measures both goods and services.

The Bottom Line

By following PPI trends, consumers and investors can avoid unexpected changes to inflation. Inflation is less dramatic than a crash, but it can be more devastating to your portfolio. 

Article Sources
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  1. United States Bureau of Labor Statistics. "Producer Price Indexes."

  2. U.S. Department of Labor, Bureau of Labor Statistics. "How Does the Producer Price Index Differ from the Consumer Price Index?"

  3. Shang-Jin Wei and Yinxi Xie.?"The Wedge of the Century: Understanding a Divergence between CPI and PPI Inflation Measures."

  4. United States Department of Labor Bureau of Labor Statistics. "Producer Price Indexes - August 2023," Page 20.

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