David Harold Blackwell (April 24, 1919 – July 8, 2010) was an American

statistician A statistician is a person who works with theoretical or applied statistics. The profession exists in both the private and public sectors. It is common to combine statistical knowledge with expertise in other subjects, and statisticians may wor ...

and

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, structure, space, models, and change. History On ...

who made significant contributions to

game theory Game theory is the study of mathematical models of strategic interactions among rational agents. Myerson, Roger B. (1991). ''Game Theory: Analysis of Conflict,'' Harvard University Press, p.&nbs1 Chapter-preview links, ppvii–xi It has appli ...

probability theory Probability theory is the branch of mathematics concerned with probability. Although there are several different probability interpretations, probability theory treats the concept in a rigorous mathematical manner by expressing it through a set o ...

information theory Information theory is the scientific study of the quantification (science), quantification, computer data storage, storage, and telecommunication, communication of information. The field was originally established by the works of Harry Nyquist a ...

, and statistics. He is one of the

eponym An eponym is a person, a place, or a thing after whom or which someone or something is, or is believed to be, named. The adjectives which are derived from the word eponym include ''eponymous'' and ''eponymic''. Usage of the word The term ''epon ...

s of the

Rao–Blackwell theorem In statistics, the Rao–Blackwell theorem, sometimes referred to as the Rao–Blackwell–Kolmogorov theorem, is a result which characterizes the transformation of an arbitrarily crude estimator into an estimator that is optimal by the mean-squa ...

. He was the first African American inducted into the

National Academy of Sciences The National Academy of Sciences (NAS) is a United States nonprofit, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the Nati ...

, the first African American tenured faculty member at the

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public land-grant research university in Berkeley, California. Established in 1868 as the University of California, it is the state's first land-grant u ...

, and the seventh African American to receive a Ph.D. in mathematics. In 2012,

President Obama Barack Hussein Obama II ( ; born August 4, 1961) is an American politician who served as the 44th president of the United States from 2009 to 2017. A member of the Democratic Party (United States), Democratic Party, Obama was the first Af ...

posthumously awarded Blackwell the

National Medal of Science The National Medal of Science is an honor bestowed by the President of the United States to individuals in science and engineering who have made important contributions to the advancement of knowledge in the fields of behavioral and social scienc ...

. Blackwell was also a pioneer in textbook writing. He wrote one of the first

Bayesian statistics Bayesian statistics is a theory in the field of statistics based on the Bayesian interpretation of probability where probability expresses a ''degree of belief'' in an event. The degree of belief may be based on prior knowledge about the event, ...

textbooks, his 1969 ''Basic Statistics''. By the time he retired, he had published over 90 papers and books on

dynamic programming Dynamic programming is both a mathematical optimization method and a computer programming method. The method was developed by Richard Bellman in the 1950s and has found applications in numerous fields, from aerospace engineering to economics. I ...

, game theory, and mathematical statistics.

Early life and education

David Harold Blackwell was born on April 24, 1919, in

Centralia, Illinois Centralia is a city in Clinton, Jefferson, Marion, and Washington counties in the U.S. state of Illinois with the largest portion in Marion County. The city is the largest in three of the counties; Clinton, Marion, and Washington, but is not a co ...

, to Mabel Johnson Blackwell, a full-time homemaker, and Grover Blackwell, an

Illinois Central Railroad The Illinois Central Railroad , sometimes called the Main Line of Mid-America, was a railroad in the Central United States, with its primary routes connecting Chicago, Illinois, with New Orleans, Louisiana, and Mobile, Alabama. A line also co ...

worker. He was the eldest of four children with two brothers, J. W. and Joseph, and one sister, Elizabeth. Growing up in an integrated community, Blackwell attended "mixed" schools, where he distinguished himself in mathematics. During elementary school, his teachers promoted him beyond his grade level on two occasions. It was in a high school geometry course, however, that his passion for math began. An exceptional student, Blackwell graduated high school in 1935 at the age of sixteen. Blackwell entered the

University of Illinois at Urbana-Champaign The University of Illinois Urbana-Champaign (U of I, Illinois, University of Illinois, or UIUC) is a public land-grant research university in Illinois in the twin cities of Champaign and Urbana. It is the flagship institution of the Univ ...

with the intent to study elementary school mathematics and become a teacher. He was a member of

Alpha Phi Alpha Alpha Phi Alpha Fraternity, Inc. () is the oldest intercollegiate historically African American fraternity. It was initially a literary and social studies club organized in the 1905–1906 school year at Cornell University but later evolved int ...

, a black fraternity that housed him for his full six years as a student. He earned his bachelor's degree in mathematics in three years in 1938 and, a year later, a master's degree in 1939. He was awarded a

Doctor of Philosophy A Doctor of Philosophy (PhD, Ph.D., or DPhil; Latin: or ') is the most common Academic degree, degree at the highest academic level awarded following a course of study. PhDs are awarded for programs across the whole breadth of academic fields ...

in mathematics in 1941 at the age of 22. His doctoral advisor was

Joseph L. Doob Joseph Leo Doob (February 27, 1910 – June 7, 2004) was an American mathematician, specializing in analysis and probability theory. The theory of martingales was developed by Doob. Early life and education Doob was born in Cincinnati, Ohio, ...

. At the time, Blackwell was the seventh African American to earn a Ph.D. in mathematics in the United States and the first at the University of Illinois at Urbana-Champaign. His doctoral thesis was on

Markov chain A Markov chain or Markov process is a stochastic model describing a sequence of possible events in which the probability of each event depends only on the state attained in the previous event. Informally, this may be thought of as, "What happe ...

Career and research

Postdoctoral study and early career

Blackwell completed one year of

postdoctoral research A postdoctoral fellow, postdoctoral researcher, or simply postdoc, is a person professionally conducting research after the completion of their doctoral studies (typically a PhD). The ultimate goal of a postdoctoral research position is to p ...

as a fellow at the

Institute for Advanced Study The Institute for Advanced Study (IAS), located in Princeton, New Jersey, in the United States, is an independent center for theoretical research and intellectual inquiry. It has served as the academic home of internationally preeminent scholar ...

(IAS) at Princeton in 1941 after receiving a Rosenwald Fellowship, which was a fund to aid black scholars. There he met

John von Neumann John von Neumann (; hu, Neumann János Lajos, ; December 28, 1903 – February 8, 1957) was a Hungarian-American mathematician, physicist, computer scientist, engineer and polymath. He was regarded as having perhaps the widest cove ...

, who asked Blackwell to discuss his Ph.D. thesis with him. Blackwell, who believed that von Neumann was just being polite and not genuinely interested in his work, did not approach him until von Neumann himself asked him again a few months later. According to Blackwell, "He (von Neumann) listened to me talk about this rather obscure subject and in ten minutes he knew more about it than I did." While a postdoc at IAS, Blackwell was prevented from attending lectures or undertaking research at nearby

Princeton University Princeton University is a private university, private research university in Princeton, New Jersey. Founded in 1746 in Elizabeth, New Jersey, Elizabeth as the College of New Jersey, Princeton is the List of Colonial Colleges, fourth-oldest ins ...

, which the IAS has historically collaborated with in research and scholarship activities, because of his race. Shabazz Blackwell Wilkins

Seeking a permanent position elsewhere, he wrote letters of application to 104

historically black colleges and universities Historically black colleges and universities (HBCUs) are institutions of higher education in the United States that were established before the Civil Rights Act of 1964 with the intention of primarily serving the African-American community. ...

in 1942, and received a total of only three offers. He felt at the time that a black professor would be limited to teaching at black colleges. Having been highly recommended by his dissertation advisor

for a position at the

, he was interviewed by statistician

Jerzy Neyman Jerzy Neyman (April 16, 1894 – August 5, 1981; born Jerzy Spława-Neyman; ) was a Polish mathematician and statistician who spent the first part of his professional career at various institutions in Warsaw, Poland and then at University College ...

. Neyman supported his appointment, and

Griffith C. Evans Griffith Conrad Evans (11 May 1887 – 8 December 1973) was a mathematician working for much of his career at the University of California, Berkeley. He is largely credited with elevating Berkeley's mathematics department to a top-tier research d ...

, the head of the mathematics department, at first agreed and even convinced university president Robert Sproul that it was the correct decision, only to subsequently balk, citing the concerns of his wife. It was customary for Evans and his wife to invite the members of the department over for dinner and "she was not going to have any darkie in her house." He was offered a post at

Southern University Southern University and A&M College (Southern University, Southern, SUBR or SU) is a public historically black land-grant university in Baton Rouge, Louisiana. It is the largest historically black college or university (HBCU) in Louisiana, a ...

at Baton Rouge, which he held in from 1942 to 1943, followed by a year as an Instructor at

Clark College Clark College is a public community college in Vancouver, Washington. With 11,500 students, Clark College is the largest institution of higher education in southwest Washington. Founded in 1933 as a private two-year junior college, Clark Colleg ...

in Atlanta.

Howard University

Blackwell joined the Mathematics Department at

Howard University Howard University (Howard) is a private, federally chartered historically black research university in Washington, D.C. It is classified among "R2: Doctoral Universities – High research activity" and accredited by the Middle States Commissi ...

in 1944. When he joined, he was one of four faculty members and within three years he was appointed full professor and head of the department. He remained at Howard until 1954. In 1947 while at Howard, Blackwell published the paper "Conditional Expectation and Unbiased Sequential Estimation", which outlined a technique that later became known as the Rao-Blackwell theorem. The

theorem In mathematics, a theorem is a statement that has been proved, or can be proved. The ''proof'' of a theorem is a logical argument that uses the inference rules of a deductive system to establish that the theorem is a logical consequence of th ...

provides a method for improving statistical estimates by potentially reducing their

mean squared error In statistics, the mean squared error (MSE) or mean squared deviation (MSD) of an estimator (of a procedure for estimating an unobserved quantity) measures the average of the squares of the errors—that is, the average squared difference between ...

. From 1948 to 1950, Blackwell spent his summers at

RAND Corporation The RAND Corporation (from the phrase "research and development") is an American nonprofit global policy think tank created in 1948 by Douglas Aircraft Company to offer research and analysis to the United States Armed Forces. It is financed ...

with Meyer Abraham Girshick and other mathematicians exploring the game theory of

duel A duel is an arranged engagement in combat between two people, with matched weapons, in accordance with agreed-upon Code duello, rules. During the 17th and 18th centuries (and earlier), duels were mostly single combats fought with swords (the r ...

s. In 1954 Girshick and Blackwell published ''Theory of Games and Statistical Decisions''. Aside from von Neumann and Girshick, other Blackwell collaborators and mentors included

Leonard J. Savage Leonard Jimmie Savage (born Leonard Ogashevitz; 20 November 1917 – 1 November 1971) was an American mathematician and statistician. Economist Milton Friedman said Savage was "one of the few people I have met whom I would unhesitatingly call a ge ...

Richard E. Bellman Richard Ernest Bellman (August 26, 1920 – March 19, 1984) was an American applied mathematician, who introduced dynamic programming in 1953, and made important contributions in other fields of mathematics, such as biomathematics. He founde ...

, and Nobel Laureate

Kenneth J. Arrow Kenneth Joseph Arrow (23 August 1921 – 21 February 2017) was an American economist, mathematician, writer, and political theorist. He was the joint winner of the Nobel Memorial Prize in Economic Sciences with John Hicks in 1972. In economics ...

University of California, Berkeley

Blackwell took a position at the

as a

visiting professor In academia, a visiting scholar, visiting researcher, visiting fellow, visiting lecturer, or visiting professor is a scholar from an institution who visits a host university to teach, lecture, or perform research on a topic for which the visitor ...

in 1954, and was hired as a

full professor Professor (commonly abbreviated as Prof.) is an academic rank at universities and other post-secondary education and research institutions in most countries. Literally, ''professor'' derives from Latin as a "person who professes". Professors ...

in the newly created Department of Statistics in 1955. He became the Statistics department chair in 1957. Blackwell bridged

topology In mathematics, topology (from the Greek language, Greek words , and ) is concerned with the properties of a mathematical object, geometric object that are preserved under Continuous function, continuous Deformation theory, deformations, such ...

and

via a game-theoretic proof of

Kuratowski's theorem In graph theory, Kuratowski's theorem is a mathematical forbidden graph characterization of planar graphs, named after Kazimierz Kuratowski. It states that a finite graph is planar if and only if it does not contain a subgraph that is a subdivi ...

in 1967. Blackwell only briefly extended his research beyond zero-sum games to explore the

sure-thing principle In decision theory, the sure-thing principle states that a decision maker who decided they would take a certain action in the case that event ''E'' has occurred, as well as in the case that the negation of ''E'' has occurred, should also take that ...

as introduced by Jimmie Savage, primarily due the real-world societal implications of the mathematical result, particularly for nuclear disarmament at the inception of the

Cold War The Cold War is a term commonly used to refer to a period of geopolitical tension between the United States and the Soviet Union and their respective allies, the Western Bloc and the Eastern Bloc. The term '' cold war'' is used because the ...

. Blackwell wrote one of the first

Bayesian Thomas Bayes (/beɪz/; c. 1701 – 1761) was an English statistician, philosopher, and Presbyterian minister. Bayesian () refers either to a range of concepts and approaches that relate to statistical methods based on Bayes' theorem, or a follower ...

textbooks, his 1969 ''Basic Statistics''. It inspired the 1995 textbook ''Statistics: A Bayesian Perspective'' by the biostatistician Donald Berry. He spent the rest of his career at UC Berkeley, retiring in 1988 at age 70, which at that time was the mandatory retirement age. Over the course of his career, he mentored over 60 students.

Personal life and death

Blackwell married Annlizabeth Madison, a 1934 graduate of

Spelman College Spelman College is a private, historically black, women's liberal arts college in Atlanta, Georgia. It is part of the Atlanta University Center academic consortium in Atlanta. Founded in 1881 as the Atlanta Baptist Female Seminary, Spelman re ...

, on December 27, 1944. They had eight children together, three sons and five daughters: Ann, Julia, David, Ruth, Grover, Vera, Hugo, and Sara. David Blackwell died of complications from a stroke on July 8, 2010, at

Alta Bates Summit Medical Center Sutter Health Alta Bates Summit Medical Center is located in the East Bay (California), East Bay of the San Francisco Bay Area. Its three hospital campuses are located in Berkeley, California, Berkeley (Alta Bates Campus, Herrick Campus) and Oaklan ...

Berkeley, California Berkeley ( ) is a city on the eastern shore of San Francisco Bay in northern Alameda County, California, United States. It is named after the 18th-century Irish bishop and philosopher George Berkeley. It borders the cities of Oakland and Emer ...

. He was 91 years old.

Honors and awards

In his lifetime, Blackwell received 12 honorary doctorates. *

Invited Speaker at the International Congress of Mathematicians This is a list of International Congresses of Mathematicians Plenary and Invited Speakers. Being invited to talk at an International Congress of Mathematicians has been called "the equivalent, in this community, of an induction to a hall of fame." ...

, 1954 * President of the

Institute of Mathematical Statistics The Institute of Mathematical Statistics is an international professional and scholarly society devoted to the development, dissemination, and application of statistics and probability. The Institute currently has about 4,000 members in all parts o ...

, 1956 * Elected a member of the

(NAS), 1965 * Elected a member of the

American Academy of Arts and Sciences The American Academy of Arts and Sciences (abbreviation: AAA&S) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, and ...

(AAAS), 1968 * President of the

Bernoulli Society for Mathematical Statistics and Probability The Bernoulli Society is a professional association which aims to further the progress of probability and mathematical statistics, founded as part of the International Statistical Institute in 1975. It is named after the Bernoulli family of mathema ...

, 1975-1977 * Honorary Fellow of the

Royal Statistical Society The Royal Statistical Society (RSS) is an established statistical society. It has three main roles: a British learned society for statistics, a professional body for statisticians and a charity which promotes statistics for the public good. ...

(RSS) in 1976 * Vice President of the

American Statistical Association The American Statistical Association (ASA) is the main professional organization for statisticians and related professionals in the United States. It was founded in Boston, Massachusetts on November 27, 1839, and is the second oldest continuousl ...

(ASA) in 1978 * Awarded the

John von Neumann Theory Prize The John von Neumann Theory Prize of the Institute for Operations Research and the Management Sciences (INFORMS) is awarded annually to an individual (or sometimes a group) who has made fundamental and sustained contributions to theory in operati ...

in 1979 * Awarded the

R. A. Fisher Lectureship The COPSS Distinguished Achievement Award and Lectureship (formerly known as R. A. Fisher Award and Lectureship) is a very high recognition of achievement and scholarship in statistical science that recognizes the highly significant impact of stat ...

in 1986 * Elected a member of the

American Philosophical Society The American Philosophical Society (APS), founded in 1743 in Philadelphia, is a scholarly organization that promotes knowledge in the sciences and humanities through research, professional meetings, publications, library resources, and communit ...

, 1990 * Fellow of the

Institute for Operations Research and the Management Sciences The Institute for Operations Research and the Management Sciences (INFORMS) is an international society for practitioners in the fields of operations research (O.R.), management science, and analytics. It was established in 1995 with the merger of ...

, 2002 * Awarded the

(posthumous), 2012

Legacy

The

Mathematical Association of America The Mathematical Association of America (MAA) is a professional society that focuses on mathematics accessible at the undergraduate level. Members include university, college, and high school teachers; graduate and undergraduate students; pure a ...

's MathFest, in coordination with the National Association of Mathematicians, features an annual MAA-NAM David Blackwell Lecture. Blackwell offered the inaugural address in 1994; and subsequent lecturers are researchers who "exemplif the spirit of Blackwell in both personal achievement and service to the mathematical community." The Blackwell-Tapia prize is named in honor of David Blackwell and

Richard A. Tapia Richard Alfred Tapia (born March 25, 1938) is an American mathematician and University Professor at Rice University in Houston, Texas, the university's highest academic title. Tapia is the Principal investigator on a $2 million NSF grant (2007-20 ...

. The University of California, Berkeley named an undergraduate residence hall in his honor, named David Blackwell Hall. The residence hall opened in Fall 2018. An educational book about his life titled ''David Blackwell and the Deadliest Duel'' was published in 2019. Blackwell made the following statement about his values and work in an 1983 interview for a project called "Mathematical People":

Basically, I'm not interested in doing research and I never have been....I’m interested in understanding, which is quite a different thing. And often to understand something you have to work it out yourself because no one else has done it.

Bibliography

Books

* *

Journal articles

* *

References

External links

Biographical sketch
from the

*
David Blackwell's oral history video excerpts
at The National Visionary Leadership Project * A volume dedicated t
David H. Blackwell
Celebratio Mathematica
Biography of David Blackwell
from the Institute for Operations Research and the Management Sciences (INFORMS)
David H. Blackwell: A Profile of Inspiration and Perseverance
University of Illinois Urbana-Champaign College of Liberal Arts & Science Department of Statistics
David Blackwell - American statistician and mathematician
from Britannica {{DEFAULTSORT:Blackwell, David 1919 births 2010 deaths People from Centralia, Illinois University of California, Berkeley College of Letters and Science faculty Institute for Advanced Study visiting scholars African-American mathematicians African-American statisticians 20th-century American mathematicians American statisticians Probability theorists Members of the United States National Academy of Sciences Presidents of the Institute of Mathematical Statistics John von Neumann Theory Prize winners Fellows of the American Statistical Association Fellows of the Institute for Operations Research and the Management Sciences National Medal of Science laureates Game theorists Academics from Illinois Mathematicians from Illinois 21st-century American mathematicians 20th-century African-American people 21st-century African-American people Members of the American Philosophical Society Mathematical statisticians University of Illinois College of Liberal Arts and Sciences alumni