Power can be defined as the ability or capacity to do something or act in a particular way, to direct or influence the behaviour of others, the course of events, or the control of resources. [1, 2]
Health policy analysis reader: the politics of policy change in low-and middle-income countries 
One relevant definition of power is that it is “the ability to influence people, and in particular to control resources”  (Buse et al., 2012:21). Such power is relational, exercised in relation to people and resources and to policy change itself. The discretionary power exercised by front-line officials in implementation, more specifically, entails choices “among possible courses of action and inaction” (Davis, 1969:4), and can be seen in, for example, the way implementors adapt or subvert policy rules, or how they engage with their clients. It occurs because there are limits on the power that can be exercised over them by higher-level authorities. Power always has multiple dimensions, however, and is generated from, or constrained by, the broader societal, political and organizational context of policy decision-making.
The classic definition is by Robert Dahl (1961) : “A has power over B to the extent that he can get B to do something that B would not otherwise do”. For instance, when a national leader resigns under threat of invasion by another country, the latter country’s government is using compulsory power to secure its preferences. Compulsory power can be used for principled ends as well. For instance, international nongovernmental organizations use shaming tactics to pressure governments to follow human rights norms.
Note: See also institutional power; structural power; productive power.
Health policy and systems research reader on human resources for health 
Power: “The ability or capacity to do something or act in a particular way” 
“The capacity or ability to direct or influence the behaviour of others or the course of events” 
World Bank 
Power is the ability of groups and individuals to make others act in the interest of those groups and individuals and to bring about specific outcomes [8,9]
PubMed Medical Subject Headings (MeSH)
The exertion of a strong influence or control over others in a variety of settings--administrative, social, academic, etc.
Year introduced: 1988
Bambra et al. (2007) 
At the general level, power is about the ability to achieve a desired outcome—power to do something—but more narrowly, it is used to mean power over something or someone and to make decisions. Influence is the external ability to have some effect on the content of these decisions. Research has linked lack of power and control with premature mortality and the social gradient of health.
Center for American Progress 
"Power is traditionally defined in foreign policy and global politics as the ability to get things done and achieve certain goals by applying resources. This definition, however, can obscure the multidirectional, multisourced, and overlapping forms of power operating in the world today. Power is far more “open sourced” than directional and/or hierarchical.
A more helpful definition of how to use power in this new context is suggested by physics: Power is measured by the rate at which work is performed or energy is converted no matter what the source. If power is more “open sourced,” or “multisource,” the key question becomes how the energy being generated can be used to bring about desired change. This kind of description of power—particularly the part about how energy is converted—is important to help us understand the power transformation occurring in geopolitics today."
10 best resources on power in health policy and systems in low- and middle-income countries, Health Policy and Planning 
To encourage further research and action using power, this article presents 10 resources that are exemplary conceptual, methodological and empirical resources pertaining to power in health policy and systems in low- and middle-income countries:
- Rushton and Williams. 2012: Frames, paradigms and power: global health policy-making under neoliberalism
- Shiffman. 2014: Knowledge, moral claims and the exercise of power in global health and global health as a field of power relations: a response to recent commentaries
- Erasmus and Gilson. 2008: How to start thinking about investigating power in the organizational settings of policy implementation
- Lehman and Gilson. 2012: Actor interfaces and practices of power in a community health program: South African study of unintended policy outcomes
- Scott et al. 2017: Negotiating power relations, gender equality, and collective agency: are village health committees transformative social spaces in northern India?
- Velloso et al. 2013: Configurations of power relations in the Brazilian emergency care system: analyzing a context of visible practice
- Daglish et al. 2015: Power and pro-poor policies ICCM in Niger
- Parkhurst et al. 2015: Doubt, defiance, and identity: understanding resistance to male circumcision for HIV prevention in Malawi
- Kapilashrami and McPake. 2013: Transforming governance or reinforcing hierarchies and competition: examining the public and hidden transcripts of the global fund and HIV in India
- McNeill et al. 2013: The global politics of health: actors and initiatives in protecting the world’s children
 The Oxford Dictionary
 Buse K, Mays N, Walt G (2012). Making health policy. Maidenhead: Open University Press
 Gilson L & Shiffman J "Power in Policy Change" in Gilson L, Orgill M, Shroff ZC, World Health Organization. A health policy analysis reader: the politics of policy change in low-and middle-income countries. World Health Organization; 2018.
 Davis KC (1969). Discretionary justice: a preliminary inquiry. Baton Rouge, LA: Louisiana State University Press
 Dahl RA (1961). Who governs? Democracy and power in an American city. New Haven, CT: Yale University Press.
 George A, Scott K, Govender V, World Health Organization. A health policy and systems research reader on human resources for health. World Health Organization; 2017.
 2017 World Development Report on Governance and the Law. Washington DC: World Bank.
 Dahl, R. A. 1957. “The Concept of Power.” Behavioral Science 2: 202–10
 Lukes, Steven. 2005. Power: A Radical Review. 2nd ed. New York: Palgrave Macmillan
 Bambra C, Fox D, Scott-Samuel A. A politics of health glossary. Journal of Epidemiology & Community Health. 2007 Jul 1;61(7):571-4.
 Heywood A. Political ideas and concepts. London: Macmillan, 1994.
 Marmot M, Wilkinson RG, eds. Social determinants of health. Oxford: Oxford University Press, 1999.
 Veena Sriram, Stephanie M Topp, Marta Schaaf, Arima Mishra, Walter Flores, Subramania Raju Rajasulochana, Kerry Scott, 10 best resources on power in health policy and systems in low- and middle-income countries, Health Policy and Planning, Volume 33, Issue 4, May 2018, Pages 611–621, https://doi.org/10.1093/heapol/czy008