FRED Data Structure

FRED (Federal Reserve Economic Data) contains over 800,000 economic time series with a well-organized hierarchical structure.

Data Hierarchy

Core Entities

Series

A series is a single economic indicator tracked over time.

series_id

string

required

Unique identifier (e.g., “GDP”, “UNRATE”, “DFF”)

title

string

Full descriptive name

observation_start

date

Date of first available data point

observation_end

date

Date of most recent data point

frequency

string

Data collection interval: Daily, Weekly, Monthly, Quarterly, Annual

units

string

Measurement units (Dollars, Percent, Index, etc.)

seasonal_adjustment

string

SA (Seasonally Adjusted), NSA (Not Seasonally Adjusted), SAAR

popularity

integer

Usage ranking from 1-100

Example Series:

{
  "id": "UNRATE",
  "title": "Unemployment Rate",
  "observation_start": "1948-01-01",
  "observation_end": "2024-09-01",
  "frequency": "Monthly",
  "frequency_short": "M",
  "units": "Percent",
  "seasonal_adjustment": "Seasonally Adjusted",
  "popularity": 95,
  "notes": "The unemployment rate represents..."
}

Observations

Individual data points within a series.

{
  "observations": [
    {
      "date": "2024-09-01",
      "value": "4.2",
      "realtime_start": "2024-10-04",
      "realtime_end": "2024-10-04"
    },
    {
      "date": "2024-08-01",
      "value": "4.3",
      "realtime_start": "2024-09-06",
      "realtime_end": "2024-09-06"
    }
  ]
}

Money, Banking & Finance

32991 - Interest rates, exchange rates, monetary aggregates

Population, Employment & Labor

10 - Demographics, employment, wages

Production & Business Activity

1 - GDP, industrial production, capacity utilization

Prices

32455 - Inflation, CPI, PPI, import/export prices

International Data

32263 - Global economic indicators

U.S. Regional Data

3008 - State and metro area statistics

Releases

Scheduled data publications from source agencies.

{
  "id": 50,
  "realtime_start": "2024-10-01",
  "realtime_end": "2024-10-01",
  "name": "Employment Situation",
  "press_release": true,
  "link": "https://www.bls.gov/news.release/empsit.htm"
}

Data Types

Economic Indicators

Labor Market
Production
Prices
Financial

Unemployment Rate (UNRATE)
Nonfarm Payrolls (PAYEMS)
Labor Force Participation (CIVPART)
Initial Jobless Claims (ICSA)
Average Hourly Earnings (CES0500000003)

Frequency Types

Frequency	Code	Typical Use Cases	Example
Daily	d	Financial markets, rates	Fed Funds Rate
Weekly	w	Claims, surveys	Initial Claims
Biweekly	bw	Specific surveys	Retail sales surveys
Monthly	m	Most indicators	Unemployment, CPI
Quarterly	q	GDP, accounts	GDP, Corporate Profits
Semiannual	sa	Some surveys	Business outlook
Annual	a	Demographics, some surveys	Population

Units and Scaling

Critical: Always check units and scalingValues may be expressed as:

Raw numbers (e.g., persons employed)
Thousands or millions (e.g., GDP in billions)
Index values (e.g., CPI with base year)
Percentages (e.g., unemployment rate)
Rates (e.g., annual rate)

Common unit types:

{
  "units": "Billions of Dollars",
  "units": "Percent",
  "units": "Index 1982-1984=100",
  "units": "Thousands of Persons",
  "units": "Index 2012=100",
  "units": "Millions of Dollars"
}

Data Transformations

Available Transformations

Transformation	Code	Formula	Use Case
Levels	lin	Raw value	Actual amounts
Change	chg	x_t - x_	Period-to-period change
Change from Year Ago	ch1	x_t - x_	Annual change
Percent Change	pch	((x_t/x_)-1)*100	Growth rates
Percent Change from Year Ago	pc1	((x_t/x_)-1)*100	Annual growth
Compounded Annual Rate	pca	(((x_t/x_)^(n))-1)*100	Annualized growth
Continuously Compounded Rate	cch	(ln(x_t)-ln(x_))*100	Log returns
Continuously Compounded Annual	cca	(ln(x_t)-ln(x_))*100	Log annual returns
Natural Log	log	ln(x_t)	Statistical analysis

Aggregation Methods

When converting frequency:

Method	Description	Best For
Average	Mean of period	Flow variables (rates, prices)
Sum	Total of period	Stock variables (production, sales)
End of Period	Last value	Levels, indices

Data Quality

Revisions

Economic data undergoes revisions:

Preliminary Release

Initial estimate based on partial data

Revised Release

Updated with more complete information

Final Release

Comprehensive data, may come months later

Annual Revisions

Methodological updates and rebasing

Vintage Data

FRED maintains historical snapshots:

{
  "realtime_start": "2024-01-05",
  "realtime_end": "2024-01-05",
  "observation_start": "2023-12-01",
  "observation_end": "2023-12-01",
  "vintage_dates": [
    "2024-01-05",
    "2023-12-08",
    "2023-11-03"
  ]
}

This allows analysis of:

Data as it was known at specific dates
Magnitude of revisions
Forecasting accuracy

Missing Values

Series may have gaps:

Discontinued series
Weekends/holidays (daily data)
Not-yet-released observations
Suppressed values (privacy/reliability)

Represented as:

{
  "date": "2024-01-01",
  "value": "."
}

Search and Discovery

Full-Text Search

Search across:

Series titles
Series descriptions
Category names
Tag names
Release names

Example:

"unemployment" → Returns ~500 series
"unemployment rate seasonally adjusted" → ~50 series
"UNRATE" → Exact match

Tag-Based Filtering

Combine multiple tags:

tags: ["monthly", "sa", "bls", "employment"]

Category Browsing

Navigate hierarchy:

Root (0)
  └─ Population, Employment & Labor Markets (10)
      └─ Current Employment Statistics (11)
          └─ [~500 series]

Common Series

Key Economic Indicators

Labor Market (Monthly)

UNRATE: Unemployment Rate (SA)
PAYEMS: Total Nonfarm Payrolls (SA)
CIVPART: Labor Force Participation Rate (SA)
U6RATE: Total Unemployed + Marginally Attached (SA)

GDP & Production (Quarterly)

GDP: Gross Domestic Product (SAAR)
GDPC1: Real GDP (SAAR)
INDPRO: Industrial Production Index (SA)
TCU: Capacity Utilization (SA)

Inflation (Monthly)

CPIAUCSL: CPI All Items (SA)
CPILFESL: CPI Less Food & Energy (SA)
PCEPI: PCE Price Index (SA)
PCEPILFE: Core PCE Price Index (SA)

Interest Rates (Daily)

DFF: Federal Funds Effective Rate
DGS10: 10-Year Treasury Constant Maturity
DGS2: 2-Year Treasury Constant Maturity
T10Y2Y: 10-Year minus 2-Year Treasury Spread

API Response Format

Series Metadata

{
  "seriess": [{
    "id": "GDP",
    "realtime_start": "2024-10-01",
    "realtime_end": "2024-10-01",
    "title": "Gross Domestic Product",
    "observation_start": "1947-01-01",
    "observation_end": "2024-04-01",
    "frequency": "Quarterly",
    "frequency_short": "Q",
    "units": "Billions of Dollars",
    "units_short": "Bil. of $",
    "seasonal_adjustment": "Seasonally Adjusted Annual Rate",
    "seasonal_adjustment_short": "SAAR",
    "last_updated": "2024-09-26 07:46:02-05",
    "popularity": 92,
    "notes": "BEA Account Code: A191RC..."
  }]
}

Observations Data

{
  "realtime_start": "2024-10-01",
  "realtime_end": "2024-10-01",
  "observation_start": "2020-01-01",
  "observation_end": "2024-04-01",
  "units": "lin",
  "output_type": 1,
  "file_type": "json",
  "order_by": "observation_date",
  "sort_order": "asc",
  "count": 18,
  "offset": 0,
  "limit": 100000,
  "observations": [...]
}

Next Steps

API Tools

Use data retrieval tools

Examples

See practical examples

Common Series

Popular indicators

Transformations

Data transformation guide

Getting Started

Core Concepts

Resources

Community

​FRED Data Structure

​Data Hierarchy

​Core Entities

​Series

​Observations

​Categories

Money, Banking & Finance

Population, Employment & Labor

Production & Business Activity

Prices

International Data

U.S. Regional Data

​Releases

​Tags

​Data Types

​Economic Indicators

​Frequency Types

​Units and Scaling

​Data Transformations

​Available Transformations

​Aggregation Methods

​Data Quality

​Revisions

​Vintage Data

​Missing Values

​Search and Discovery

​Full-Text Search

​Tag-Based Filtering

​Category Browsing

​Common Series

​Key Economic Indicators

​API Response Format

​Series Metadata

​Observations Data

​Next Steps

API Tools

Examples

Common Series

Transformations

FRED Data Structure

Data Hierarchy

Core Entities

Series

Observations

Categories

Releases

Tags

Data Types

Economic Indicators

Frequency Types

Units and Scaling

Data Transformations

Available Transformations

Aggregation Methods

Data Quality

Revisions

Vintage Data

Missing Values

Search and Discovery

Full-Text Search

Tag-Based Filtering

Category Browsing

Common Series

Key Economic Indicators

API Response Format

Series Metadata

Observations Data

Next Steps