Non-Seasonally Adjusted (NSA) data refers to raw economic or financial figures that have not been modified to remove predictable, seasonal fluctuations. Think of it as the unedited, behind-the-scenes footage of the economy. Economic activity rarely moves in a straight line; it ebbs and flows with the seasons. For example, retail sales naturally spike during the holiday season, and construction activity typically slows down in the cold winter months. NSA data captures these real-world peaks and valleys exactly as they occurred. The alternative is Seasonally Adjusted (SA) data, where statisticians apply models to smooth out these predictable patterns, theoretically making it easier to spot underlying trends. However, for the discerning investor, the raw NSA figures often tell a more honest and direct story, especially when viewed through the right lens.
In a world filled with financial commentary and analysis, NSA data is your direct line to the unvarnished truth. While polished, seasonally adjusted numbers have their place, understanding the raw data gives you an edge in cutting through the noise and making your own informed judgments.
Imagine you're looking at two photos of a person. One is a raw, unedited snapshot (NSA), and the other is a carefully airbrushed and filtered image from social media (SA). The edited photo might look smoother and more appealing at a glance, but the unedited one shows you what's really there, including the “imperfections” that tell the full story. Similarly, SA data is an interpretation—a model's best guess at what a trend looks like without seasonal effects. Different agencies can use slightly different models, leading to revisions and variations. NSA data, on the other hand, is the concrete number. It’s what a company actually sold or what the unemployment rate truly was in a specific month, without any statistical wizardry. For an investor practicing value investing, focusing on verifiable facts over abstract models is paramount.
This is where NSA data truly shines for investors. Comparing NSA figures from one quarter to the next (e.g., Q4 vs. Q3) can be wildly misleading. Of course a toy company's sales fell after the holidays! That's not news; it's just the season. The real magic happens when you compare the same period across different years. This is called a year-over-year (YoY) comparison. By comparing Q4 2023 sales with Q4 2022 sales using NSA data, you are making an apples-to-apples comparison. You are comparing two holiday seasons directly. This method naturally accounts for seasonality and reveals the company's true underlying growth or decline. Did the company have a better holiday season this year than last? That’s a question that gets to the heart of a business's performance.
Let's put this into practice. You are analyzing a home improvement retailer like The Home Depot.
You can find NSA data in company financial reports (like 10-Q or 10-K filings) and from official sources like the U.S. Bureau of Labor Statistics (for employment data) or the U.S. Census Bureau (for retail sales).
When you see economic data, knowing whether it's NSA or SA helps you ask the right questions. Here’s a simple breakdown.