Table of Contents
Notes-Bibliography vs Author-Date
Chicago style offers two parallel systems:
| System | In-text marker | Source list name | Common disciplines |
|---|---|---|---|
| Notes-Bibliography (NB) | Superscript footnote/endnote | Bibliography | History, literature, arts, humanities |
| Author-Date (AD) | Parenthetical (Author Year) | Reference List | Sciences, social sciences, education |
This guide covers the Author-Date system. If your assignment requires footnotes, see the Chicago Notes-Bibliography guide.
In-Text Citation Format
Chicago Author-Date in-text citations consist of the author's last name, year of publication, and — when quoting directly — a page number, all placed inside parentheses.
Basic format
(Author LastName Year)(Author LastName Year, page)
Paraphrase
Economic inequality has widened significantly since the 1980s in most OECD countries (Piketty 2014).
Direct quote
Piketty (2014, 571) argued that "the distribution of wealth is one of today's most widely discussed and controversial issues."
Narrative — paraphrase
Piketty (2014) documented the widening of economic inequality across OECD countries.
Two authors
(Deaton and Case 2020)
Deaton and Case (2020) documented…
Deaton and Case (2020) documented…
Three or more authors
(Smith et al. 2022)
Smith et al. (2022) found…
Smith et al. (2022) found…
No comma between author and year
Chicago Author-Date writes (Smith 2022) — there is no comma between the author and year. This differs from APA 7, which writes (Smith, 2022).
Multiple sources in one citation
(Acemoglu and Robinson 2012; Piketty 2014; Stiglitz 2012)
List alphabetically by author, separated by semicolons.
The Reference List
The reference list appears at the end of the paper under the heading References. Entries are sorted alphabetically by the first author's last name. Use a hanging indent (first line flush, subsequent lines indented 0.5 inches). Double-spacing is standard in most academic submissions.
Books
Format — single author
Last, First. Year. Title of Book. Place: Publisher.
Piketty, Thomas. 2014. Capital in the Twenty-First Century. Cambridge, MA: Harvard University Press.
Format — two authors
Last, First, and First Last. Year. Title. Place: Publisher.
Deaton, Angus, and Anne Case. 2020. Deaths of Despair and the Future of Capitalism. Princeton: Princeton University Press.
Format — 3–10 authors
List all authors. First author: Last, First; remaining: First Last. Year. Title. Place: Publisher.
Journal Articles
Format — print journal
Last, First. Year. "Article Title." Journal Name Volume (Issue): Pages.
Autor, David H. 2014. "Skills, Education, and the Rise of Earnings Inequality Among the 'Other 99 Percent.'" Science 344 (6186): 843–851.
Format — online journal with DOI
Last, First. Year. "Article Title." Journal Name Volume (Issue): Pages. https://doi.org/XXXXX.
Chetty, Raj, David Grusky, Maximilian Hell, Nathaniel Hendren, Robert Manduca, and Jimmy Narang. 2017. "The Fading American Dream: Trends in Absolute Income Mobility since 1940." Science 356 (6336): 398–406. https://doi.org/10.1126/science.aal4617.
Websites & Online Sources
Format — webpage with author
Last, First. Year. "Page Title." Website Name. Month Day, Year. URL.
Ortiz-Ospina, Esteban. 2023. "Global Education." Our World in Data. January 15, 2023. https://ourworldindata.org/global-education.
Format — webpage, no author
Organisation Name. Year. "Page Title." Website Name. Accessed Month Day, Year. URL.
World Health Organization. 2024. "Mental Health." WHO. Accessed March 10, 2024. https://www.who.int/health-topics/mental-health.
Access dates
Chicago Author-Date recommends including an access date for web pages that may change over time and have no publication date. For stable, dated pages it is optional.
Reports & Grey Literature
Government / institutional report
Organisation. Year. Report Title. Report no. (if any). Place: Publisher. URL.
International Monetary Fund. 2023. World Economic Outlook: A Rocky Recovery. Washington, DC: IMF. https://www.imf.org/en/Publications/WEO.
Edited Volumes & Book Chapters
Chapter in an edited book
Last, First. Year. "Chapter Title." In Book Title, edited by First Last, Pages. Place: Publisher.
Acemoglu, Daron. 2008. "Oligarchic versus Democratic Societies." In Understanding Institutions, edited by Mary Douglas, 45–82. Princeton: Princeton University Press.
No Author / No Date
| Situation | In-text | Reference list — starts with: |
|---|---|---|
| No author | (Title Fragment Year) or ("Title Fragment" Year) | Title of work (alphabetised) |
| No date | (Smith n.d.) | Smith, John. n.d. Title.… |
| Organisation as author | (WHO 2024) | World Health Organization. 2024.… |
Chicago Author-Date vs APA 7 — Key Differences
| Feature | Chicago Author-Date | APA 7 |
|---|---|---|
| Author–year separator | No comma: (Smith 2022) | Comma: (Smith, 2022) |
| Page number in in-text | (Smith 2022, 44) | (Smith, 2022, p. 44) |
| Journal article title | "Article Title" (roman) | Article title (no italics, no quotes, sentence case) |
| Book title in reference list | Title Case Italics | Sentence case italics |
| Source list title | References | References |
| DOI format | Full URL: https://doi.org/… | Full URL: https://doi.org/… |
| Publisher location | Required | Omitted |