Research transparency

Data Sources & Methodology

How Presidential Data Atlas presents historical statistics, calculates comparisons, and handles gaps and limitations.

Important interpretation note

A statistic measured during a presidency is not proof that the president caused it. Economic outcomes are influenced by Congress, the Federal Reserve, international events, business cycles, earlier policies, and data revisions. Comparisons describe observed conditions; they are not presidential performance grades.

Primary data providers and references

These agencies and repositories support the site's subject areas. For a particular metric, consult its definition below and the Sources & Methodology selector in the comparison table.

U.S. Bureau of Labor Statistics (BLS) ↗

Unemployment and consumer price statistics. The economic trends chart uses monthly BLS observations.

U.S. Bureau of Economic Analysis (BEA) ↗

Real GDP and related national economic accounts. Quarterly GDP growth is annualized from consecutive real GDP levels.

U.S. Department of the Treasury ↗

Federal debt and fiscal data. National debt is a stock at two reporting dates; deficits are flows over time.

U.S. Department of Homeland Security (DHS) ↗

Historical immigration statistics, including removals, returns, lawful permanent residents and refugees where available.

Federal Reserve Economic Data (FRED) ↗

Public access and documentation for many economic time series; series definitions and original publishers should be checked for each metric.

Office of Management and Budget (OMB) ↗

FY 2027 Historical Tables: national defense outlays (Table 3.1), total federal outlays (Table 1.1), and fiscal-year GDP and defense-specific inflation deflators (Table 10.1). Actual fiscal years 1940–2025.

U.S. Census Bureau ↗

Household income and other historical population/economic series where applicable.

How comparisons are calculated

Administration boundaries. Observations are grouped by presidential administration and the dates covered by each series. Nonconsecutive presidencies are separate administrations. Monthly, quarterly, annual, and fiscal-year figures may not align exactly with inauguration dates.

Average, starting, and ending values. Where available, the table reports the arithmetic average of assigned observations and the first and last observed values. These are different from a cumulative change. Observation counts and gaps matter when comparing unequal terms.

Inflation. The monthly inflation trend uses the year-over-year CPI percentage change. Cumulative inflation compares the CPI index at a baseline and ending observation; it should not be calculated by summing monthly year-over-year rates.

Real GDP. The trend chart computes annualized quarter-over-quarter growth from BEA real GDP levels: ((current quarter / previous quarter) ^ 4 − 1) × 100. Cumulative real GDP growth and average quarterly annualized growth answer different questions.

Federal deficit versus national debt. Deficit figures accumulate monthly fiscal flows over a period; debt change subtracts the starting debt stock from the ending stock. These quantities are not interchangeable. Earlier debt observations may use fiscal-year-end annual estimates rather than daily figures.

Immigration. Formal removals, returns, refugee admissions, and lawful permanent residence are distinct categories. Historical data may be reported by fiscal year and should not be treated as exact inauguration-to-inauguration totals.

Current and incomplete terms. Results for an ongoing administration are provisional. Missing observations are shown as N/A rather than estimated. Data providers may revise historical values after publication.

Historical events. The timeline uses curated event dates and references. Events overlapping an administration are contextual annotations, not evidence of causation.

Military & National Defense

The four defense-spending metrics use actual fiscal-year data from the U.S. Office of Management and Budget’s FY 2027 Historical Tables. National Defense is budget function 050, which is broader than Department of Defense spending alone.

Average Annual Defense Spending (2017 Dollars): The arithmetic average of national defense outlays for assigned fiscal years, adjusted to constant FY 2017 dollars using the Total Defense composite outlay deflator in OMB Table 10.1. Reported in billions.

Defense Spending (% of GDP): The arithmetic mean of each fiscal year’s defense outlays divided by that fiscal year’s GDP, multiplied by 100. This is not the ratio of total defense spending to total GDP across the term.

Defense Spending (% of Federal Budget): The arithmetic mean of annual national defense outlays divided by total federal outlays (including on-budget and off-budget spending), multiplied by 100.

Defense Spending Change During Presidency (%): The percent change between the first and last attributed fiscal years’ defense outlays, both adjusted for inflation. At least two fiscal years are required; otherwise the value is N/A.

Presidential attribution: Each fiscal year is assigned to the president serving on September 30. Fiscal years that span a presidential transition contain spending under two administrations. These are fiscal-year approximations, not exact inauguration-to-inauguration totals, and they do not establish causation.

Coverage and limitations: Actual FY 1940–2025 data. FDR’s earlier years are not covered. Results for the current administration are provisional and will change as actual data becomes available. OMB may revise historical figures.

Official source: OMB Historical Tables ↗ — Tables 1.1, 3.1, and 10.1.

Presidential Approval Ratings

Source: Gallup historical presidential job approval statistics. Approval measures the share of respondents who approve of how a president is handling the job; it is not an objective presidential performance rating.

Average approval: Gallup's published average over a presidency, not a simple average of the highest and lowest readings. Highest / lowest: Highest and lowest reported Gallup job-approval percentages. Final: Last available Gallup approval reading before leaving office, where a comparable reading exists.

Coverage: Completed administrations from Truman through Biden. FDR is not included in the comparable published summary. Nonconsecutive administrations are treated separately. The current Trump term is N/A until a documented, consistent source methodology is established.

Interpretation: Polling dates, sample designs, question wording, frequency, and margins of error affect comparisons. Approval can shift with events outside a president's control. Values should not be interpreted as precise rankings of presidential effectiveness.

Gallup historical presidential approval statistics ↗

Metric definitions from the dataset

Definitions and calculation notes below come from the metric metadata stored with the site. Some metrics have no additional published notes.

Civilian Unemployment Rate(percent)

Monthly seasonally adjusted unemployment rate for the civilian labor force age 16 and older.

Frequency: monthly

Calculation: Arithmetic mean of available monthly observations.

Notes: Each monthly observation is assigned to the president serving on the first day of its reference month. Averages are based on available observations. Incomplete historical coverage is disclosed.

CPI-U Index (Raw)(index)

Underlying monthly CPI-U index used to derive inflation rates; not itself an inflation rate.

Frequency: monthly

Calculation: source_index_only

Notes: Not for direct cross-presidency comparison using arithmetic averages. Keep hidden from the main metric selector.

Federal Monthly Deficit(USD billions)

Federal monthly unified budget deficit (positive) or surplus (negative), billions of nominal USD.

Frequency: monthly

Calculation: monthly_budget_deficit

Notes: The headline is the SUM of monthly deficit/surplus amounts, not their average. Source: MTS Table 1 current_month_dfct_sur_amt (positive deficit, negative surplus), converted to billions. One observation per calendar month, dated at month-end. The January inauguration month belongs to the incoming president. Figures are nominal, not inflation-adjusted.

Inflation Rate(%)

Monthly year-over-year percentage change in the CPI-U All Items index (not seasonally adjusted).

Frequency: monthly

Calculation: year_over_year_percent_change

Notes: Each monthly rate compares the CPI index with the same month 12 months earlier. The table average is the arithmetic mean of available monthly annual inflation rates, not cumulative inflation. Starting/ending are first/last observed rates within an administration.

Real Median Household Income(USD (inflation-adjusted))

Median annual household income in the United States, adjusted for inflation.

Frequency: annual

Calculation: annual_median_household_income

Notes: Annual U.S. Census Bureau estimates. Values are adjusted for inflation to a common dollar year. Presidential comparisons use the latest available annual observation before an inauguration as the starting baseline and the latest available annual observation before the next inauguration as the ending value. Annual observations do not represent exact inauguration-day income. Current-administration values are provisional.

Total National Debt Outstanding(USD trillions)

Total federal debt outstanding, including debt held by the public and intragovernmental holdings.

Frequency: daily

Calculation: point_in_time_balance

Notes: Values are sourced from Treasury daily observations. Starting and ending presidential debt will use observations at administration boundaries.

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Data freshness and corrections

The site does not currently publish a verified last-refresh timestamp for every dataset. Do not assume the most recent official release has been imported. Refer to the original source for the latest revisions. Missing or inconsistent values should be investigated before drawing conclusions.