Mathematica Policy Research is a policy research organization with offices in Princeton, New Jersey; Cambridge, Massachusetts; Chicago, Illinois; Washington, DC; Ann Arbor, Michigan; and Oakland, California.  Mathematica has more than 1,000 employees and conducts program evaluation, policy research and interpretation, survey design and data collection, and performance measurement and data management. Mathematica works across the United States and in countries around the world for clients that include federal agencies, state and local governments, foundations, universities, and private-sector and international groups.
Samuel G. Barton   founded the Industrial Surveys Company in the late 1930s. His company later became Market Research Corporation of America. The latter formed a unit named Mathematica, which in 1969 "was spun off ... to allow for faster growth."  Oskar Morgenstern was the first chairman of Mathematica, Inc.
Mathematica had three divisions:
- Mathematica Products Group - best known for developing RAMIS (software).
- MathTech, the company's technical and economic consulting group - "research projects and computer systems other than Ramis." .
- Mathematica Policy Research (MPR). This unit's strength was in "social experiments and surveys."  In 1983 MPR reported "a major survey assignment for the American Medical Association."
A quarter of a century after Mathematica's founding, it "was largely owned by a group of professors in Mathematics and Economics at Princeton University ... as this group aged, they opted to cash out by selling." The result was a 3-way split:
- Mathematica Products Group was sold in 1983, eventually becoming part of Computer Associates.
- MathTech became an employee-owned company in 1986, as did Mathematica Policy Research, the only unit still carrying the Mathematica name.
In 1968, the pre-split Mathematica company conducted the first social policy experiment in the United States, the New Jersey Income Maintenance Experiment (an experimental study of a negative income tax), to test ways of encouraging low-income individuals to work. 
In 1975, it was incorporated under its present name, as part of Mathematica, Inc. In 1986, the firm became employee-owned, and the only firm using the Mathematica name.
In early 1995, Mathematica formed a research affiliate, the Center for Studying Health System Change, which provides objective analyses of how the country’s changing health care system affects individuals and families.
In 2007, the company launched the Center for Studying Disability Policy (CSDP), to inform disability policy formation with rigorous, objective research, and data collected from the people disability policy aims to serve. CSDP provides leadership and support for disability research and data collection conducted by Mathematica.
In early 2008, Mathematica created the Center for Improving Research Evidence (CIRE), to identify, assess, and disseminate results from quality, rigorous research to inform evidence-based policymaking. CIRE also provides technical assistance in designing, conducting, assessing, and using a range of scientific policy research and evaluations to support a growing national and international research base.
In 2010, Mathematica established the Center on Health Care Effectiveness (CHCE), a resource for policymakers, the public, and other stakeholders, offering expertise and scientific methods to address real-world issues faced by patients, providers, and innovators to improve health care.
In 2013, Mathematica established the Center for International Policy Research and Evaluation (CIPRE). Its focus is to provide high quality, objective and rigorous research-based information to funders and policymakers addressing global development issues.
Mathematica has five divisions: data analytics, health, human services, international research, and survey. Mathematica's research fields include disability, early childhood, education, family support, health, international, labor, and nutrition.
Within these areas, Mathematica provides services such as program evaluation and policy research, survey design and data collection, research assessment and interpretation, and program performance and data management.
-  Archived July 9, 2011, at the Wayback Machine.
- 1914 - Jan.23, 1982: Age 68
- "SAMUEL G. BARTON, 68, A MARKETING SPECIALIST". NYTimes.com. January 29, 1982.
- Karen W. Arenson (February 22, 1983). "MATHEMATICA'S SHIFT INTO SOFTWARE FIELD". The New York Times.
- "NIT Archive". Wisc.edu. Retrieved 28 March 2015.
- "What the Research Says..." (PDF). Siecus.org. Retrieved 2015-05-16.
-  Archived September 29, 2011, at the Wayback Machine.