Postdoctoral research is scholarly research conducted by a person who has completed doctoral studies. It is intended to further deepen expertise in a specialist subject, including integrating a team, acquiring novel skills and methods. Postdoctoral research is often considered essential while advancing the scholarly mission of the host institution; it is expected to produce relevant publications. In some countries, postdoctoral research may lead to further formal qualifications or certification, while in other countries it does not. A 1999 study found that the 43% of the first authors of research articles published in Science were by postdoctoral fellows hence contributing with a great percentage of the carried out highest impact research.
Postdoctoral research may be funded through an appointment with a salary or an appointment with a stipend or sponsorship award. Appointments for such a research position may be called Postdoctoral Research Fellow, Postdoctoral Research Associate, or Postdoctoral Research Assistant. Depending on the type of appointment, postdoctoral researchers may work independently or under the supervision of a principal investigator. However, a designated postdoctoral research appointment may also be taken up when other suitable positions are not available, rather than merely pursuing the deepening of scholarly experience. In many English-speaking countries, postdoctoral researchers are colloquially referred to as "postdocs".
In several countries, such as the UK and the US, postdoctoral positions are an alternative to conduct research with no teaching duties.
United Kingdom 
Since the landmark ruling in the employment tribunal (Scotland) Ball vs Aberdeen University 2008 case (S/101486/08), researchers who have held successive fixed-term contracts for four years service are no longer temporary employees but are entitled to the open-ended contracts.
United States 
In the US, a postdoctoral scholar ("postdoc") is an individual holding a doctoral degree who is engaged in a temporary period of mentored research and/or scholarly training for the purpose of acquiring the professional skills needed to pursue a career path of his or her choosing. The National Postdoctoral Association (NPA) is a member-driven organization that provides a voice for postdoctoral scholars in the United States.
There are no comprehensive data of postdocs in the US because of the less organized survey and the difficulty in counting international postdocs. Actually, the proportion of postdocs on temporary visas reached 53.6% in 2010.
Regarding the major field of the US’s postdocs, life sciences have greater share than other fields due to much federal funding in life and medical science areas since mid 1990. One survey shows that 54% of postdocs major in life sciences, in contrast, those who majored in physical science, mathematics, and engineering account for 28%.
Postdocs play an important role in leading research activity in the US. The median salary of postdocs is $42,000 a year up to 5 years after receiving their doctoral degrees, 44% less than that of tenured positions.
In 2010, postdoctoral researchers in California formed a union in order to secure better working conditions, such as the right to file a complaint, for alleged discrimination or sexual harassment, through a formal grievance procedure. In California, new postdoctoral appointments receive at least the NIH postdoctoral minimum salary ($39,264 in 2011) and many receive annual pay raises of 5-7% or more in accordance with the NIH’s Ruth L. Kirschstein National Research Service Awards (NRSA).
Postdoctoral research may be required for obtaining a tenure-track faculty position, especially at research-oriented institutions. Post-doctoral appointments that were traditionally optional have become mandatory in some fields as the degree of competition for tenure-track positions in academia has significantly increased over previous decades. In fact, the small supply of the professional positions in academia compared to the growing number of postdocs makes it difficult to find tenure-track positions. In 2008, the proportion of those who got a tenure or tenure-track within 5 years after they received a doctoral degree is about 39%; nearly 10% of postdocs were still waiting for tenure-track positions over 40 in 2003.
On the other hand, 85 percent of engineering doctoral degree recipients is likely to go initially into business or industry sector. Under the circumstances, providing doctoral students as well as postdocs with necessary skills for nonacademic positions has become one of the important roles for graduate schools and institutions. The America COMPETES Act recognized the importance of graduate student support for obtaining skills needed when they pursue nonacademic careers, and required National Science Foundation (NSF) to increase or decrease funding for the Integrative Graduate Education and Research Traineeship (IGERT) programs at least at the same rate as it increases or decreases funding for the Graduate Research Fellowship program. IGERT has been providing Ph.D. graduate students with more interdisciplinary experience, broad based professional and technical skill, various training needed in nonacademic careers, off-campus internships and career information since 1998.
Salaried appointments at the minimum Level A, Step 6 for academic salaries, for doctoral qualified employees (beginning in 2008) are set at A$75,612 p.a. at the University of Sydney, A$75,404 p.a. at the University of Melbourne, and A$75,612 p.a. at the University of New South Wales.
Alternatively the Australian Research Council (ARC) provides Postdoctoral Fellowships. For example their Discovery Projects, funds 3 year Fellowships, beginning in 2009, with A$61,399 p.a. Furthermore, a mandatory superannuation payment of 11-17% is paid by Universities.
See also 
- Doctor of Juridical Science
- EURODOC—European Council of Doctoral Candidates and Junior Researchers
- European Research Charter
- National Postdoctoral Association—NPA (USA)
- Research associate
- Research fellow
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- Discovery Projects - Australian Research Council (ARC)
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