An economist is an expert in the social science of economics. The individual may also study, develop, and apply theories and concepts from economics and write about economic policy. Within this field there are many sub-fields, ranging from the broad philosophical theories to the focused study of minutiae within specific markets, macroeconomic analysis, microeconomic analysis or financial analysis, involving analytical methods and tools such as econometrics, statistics, economics computational models, financial economics, financial mathematics and mathematical economics.
 In academia
The professionalization of economics, reflected in academia, has been described as "the main change in economics since around 1900." Most major universities have an economics faculty, school or department, where academic degrees are awarded in economics. However, many prominent economists come from a background in mathematics, engineering, business, law, sociology, or history.
The Nobel Memorial Prize in Economics is a prize awarded to economists each year for outstanding intellectual contributions in the field of economics. The Prize Winners are announced in October every year. They receive their awards (a prize amount, a gold medal and a diploma) on December 10, the anniversary of Alfred Nobel's death. 
Economists work in many fields including academia, government and in the private sector, where they may also “...study data and statistics in order to spot trends in economic activity, economic confidence levels, and consumer attitudes. They assess this information using advanced methods in statistical analysis, mathematics, computer programming...and “... they make recommendations about ways to improve the efficiency of a system or take advantage of trends”. as they begin. .
It is more difficult to define the professional category of "economists" than to define regulated professions such as engineering, law or medicine. While a lawyer, for example, may be generally defined as a person possessing a law degree and state license to practice law, there is not a legally-required educational requirement or license for economists. In some job settings, the possession of a Bachelor's or Master's degree in economics is considered the minimum credential for being an economist. However, in some parts of the US government, a person can be considered an economist as long as they have four or more university courses in economics. As well, a person can gain the skills required to become a professional economist in other related disciplines, such as statistics or some types of applied mathematics, such as mathematical finance or game theory.
A professional working inside of one of many fields of economics or having an academic degree in this subject is widely considered to be an economist, and any person within any of these fields can claim to be one. Economists are also employed in banking, finance, accountancy, commerce, marketing, and business administration.
 By country
Economics graduates are employable in varying degrees, depending on the regional economic scenario and labour market conditions at the time for a given country. Apart from the specific understanding of the subject, employers value the skills of numeracy and analysis, the ability to communicate and the capacity to grasp broad issues which the graduates acquire at the university or college. Whilst only a few economics graduates may be expected to become professional economists, many find it a base for entry into a career in finance – including accounting, insurance, tax and banking, or management. A number of economics graduates from around the world have been successful in obtaining employment in a variety of major national and international firms in the financial and commercial sectors, and in manufacturing, retailing and IT, as well as in the public sector – for example, in the health and education sectors, or in government and politics. Small numbers go on to undertake postgraduate studies, either in economics, research, teacher training or further qualifications in specialist areas.
 United States
According to the United States Department of Labor there were 13,000 economists in the US with a median salary of roughly $72,780 with the top ten percent earning more than US$ 129,170 annually. About 400 colleges and universities grant about 900 new Ph.D.s in economics each year. The type of academic degree, Bachelors, Masters or Doctorate degree had significant influence on an individuals job outlook and salary. While the overall expected job growth for economists remains below nation average, the demand for those with a Doctorate, especially those employed in the corporate sector, is expected to increase at a considerably faster pace. Incomes were highest for those in the private sector, followed by the federal government with academia and high schools paying the lowest incomes. Median salaries ranged from $45,000 for those with a Bachelor to $85,000 for those with a Ph.D. in economics. A recent and continuous study by PayScale.com showed Economic consultants with a Ph.D. had the overall highest median income for any group making $116,250, the median salaries for an assistant professor was $63,500, for an associate professor it lay at $67,000 and $85,000 for a full professor. The overall median income for doctorates in academia was $75,000 compared to $125,000 in consulting and $87,000 in banking.
Policy advising and analyzing of economic current trends are among the main responsibilities of economists in the United States. A recent study of U.S. economists by Daniel B. Klein and Charlotta Stern found that the responses show that most economists are supporters of safety regulations, gun control, redistribution, public schooling, and anti-discrimination laws. They are evenly mixed on personal choice issues, military action, and the minimum wage. Most economists oppose tighter immigration controls, government ownership of enterprise and tariffs. A study in the Southern Economic Journal found that "71 percent of American economists believe the distribution of income in the US should be more equal, and 81 percent feel that the redistribution of income is a legitimate role for government." In terms of political orientation 63% identified as progressive and less than 20% as conservative/libertarian with registered Democrats outnumbering registered Republicans 2.8:1.
 United Kingdom
Analysis of destination surveys for economics graduates from a number of selected top schools of economics in the United Kingdom (ranging from Newcastle University to the London School of Economics), shows nearly 80 per cent in employment six months after graduation – with a wide range of roles and employers, including regional, national and international organisations, across many sectors. This figure compares very favourably with the national picture, with 64 per cent of economics graduates in employment.
 Famous economists
Early economists were found in the Ancient Greek world, with Aristotle (382-322 BC) expounding in his work Topics on the topic of human production and further examining the topic in Politics. Xenophon (431-355) also wrote extensively on the Athenian economy in his work Economics.  According to some historians, "the pioneer economist of the world" was Chanakya (c. 350-283 BC) an adviser and prime minister to the first Maurya Emperor Chandragupta from 340-293 BC. In the 1700s, one of the first economic writers was Richard Cantillon (1680-1734), who wrote the treatise Essai Sur la Nature du Commerce en Général. Early founders of economic concepts included the Scottish philosopher, economist, and historian. David Hume 1711-1776) and the so-called "classical economists": English demographer and political economist Thomas Malthus (1766-1834), political economist David Ricardo (1772–1823), and the Scottish moral philosopher and political economist Adam Smith (1723-1790).
Other early developers of economic concepts include the British philosopher, political economist John Stuart Mill (1806–1873); French economist and free trade advocate Jean-Baptiste Say (1767–1832); Prussian philosopher, political economist, and revolutionary Karl Marx (1818–1883); French classical liberal theorist and political economist, Frédéric Bastiat (1801–1850); and English economist and logician William Stanley Jevons (1835-1882).
Founders of important economic concepts who were alive during the 20th century include the Austrian economist Eugen von Böhm-Bawerk (1851–1914); the founder of the Austrian School of economics, Carl Menger (1840–1921); British economist, developer of Keynesian economics, and influential founders of modern theoretical macroeconomics John Maynard Keynes (1883–1946); American economist, health campaigner, and eugenicist Irving Fisher (1867-1947); German economist and proponent of the social market economy, Wilhelm Röpke (1899-1966); American economists, Nobel Prize Laureate and proponent of the Tobit model, James Tobin (1918-2002); Austrian-British member of the Austrian School of economics Friedrich Hayek (1899-1992); and American economist, public intellectual, and laissez-faire capitalism advocate Milton Friedman (1912–2006).
Current well-known American economists include Paul Krugman, a public intellectual, advocate of modern liberal policies, known for his descriptions of rising inequality; Jeffrey Sachs, former United Nations economic adviser to the Secretary-General and author of The End of Poverty; and Alan Greenspan, the former chairman of the Federal Reserve.