The Wikipedia definition of sabbatical doesn't match how I think of an academic sabbatical. What does it mean to go on academic sabbatical, and does it depend on the country?
The definition of sabbatical in Wikipedia refers to labor terminology rather than academic sabbatical leave. As a privilege to employees, they can have temporary unpaid leave (for any personal reason) without losing their job.
However, academic sabbatical historically is somehow different. When a scholar needs peace of mind to focus on a challenging issue, s/he will visit a new institute to experience a new atmosphere. While still being in the academic environment, not having heavy official duties.
There are several motivations for a sabbatical leave (at least as I have seen):
A manager finishes an administrative position (e.g. Dean), and wishes to rest in a different atmosphere, but not far from academia.
A researcher working on a new idea, prefers to focus on his/her work somewhere with less commitments on everyday responsibilities (e.g. teaching, advising, etc).
A researcher is exploring new possibilities and opportunities, spend some time in a new department to live with new colleagues for a while.
A researcher is collaborating with another group and spend a year in the host research group as a visiting scientist/professor while being on sabbatical leave from his/her institute.
A professor in a mid-level university finds a temporary position in a top university. This is the base for many visiting professors in the US universities, e.g. international professors can experience working in the US universities. Even there are associate/assistant professors who find a post-doc position in the top universities, and use sabbatical leave, not to lose their job at home.
In any case, sabbatical allowance mainly depends on the university employment rules.
Situations will depend widely on country and on the employer, because a sabbatical leave is something between you and them: it's an arrangement between an academic and her employer that lets her “take a break” without fully losing the benefits of their position.
The nature of the break, the activities one has during the sabbatical, and the benefits retained during the length of the sabbatical can vary completely. For example, a sabbatical can take the form of an unpaid leave for six months or a year, during which the researcher will sail around the world. However, in the modern research system, sabbaticals generally consist of periods where the academic gets time to:
- focus full time on a given research project (most often, an emerging project)
- visit another group to advance an existing project or help create a new collaboration
- spend part time or full time launching a research-related business
It is common for universities to support those researchers who are granted sabbaticals with some income, typically somewhere between half salary and full salary.
You can browse the web to see sabbatical policies at various universities. Here's the description at U. Oregon:
Sabbatical leave is a paid period of released time designed to reinvigorate and restore one's academic energies, and to provide a base for future intellectual development and achievement. During the leave period, a faculty member may receive between 50 and 100 percent of salary depending on the length of the leave and the school, college or other administrative affiliation.