Health economics is the application of economic science in the field of health. This science is unknown despite a strong increase in its use in recent decades. In the medical field, its application is more and more widespread thanks to the economic project analysis techniques. Economists are divided over the scientific validity of project analyses. The macro economy of the health of the economy's health is often the first presented either analysis of consumption of care, general production in different countries, the health of populations and equity in health care. On the other hand, health economists will generally focus primarily on the health economics micro aspects. This aspect of this science is more pointed, and more scientific and sophisticated. The microeconomics of health studied the behaviour of economic agents or medical doctors, pharmacists, nurses, patients, managers, institutions of health, public and private insurers, non-profit companies, private clinics, pharmaceutical and generic companies. The study of the pharmaceutical sector and these different economic agents is often called the pharmaceutical economy.