Wiktionary
n. common good.
Wikipedia
Public interest, according to the Random House Dictionary, is "1. the welfare or well-being of the general public; commonwealth. 2. appeal or relevance to the general populace: a news story of public interest."
Economist Lok Sang Ho in his Public Policy and the Public Interest (Routledge, 2012, published 2011) argues that the public interest must be assessed impartially and, therefore, defines the public interest as the " ex ante welfare of the representative individual." Under a thought experiment, by assuming that there is an equal chance for one to be anyone in society and, thus, could benefit or suffer from a change, the public interest is by definition enhanced whenever that change is preferred to the status quo ex ante. This approach is "ex ante", in the sense that the change is not evaluated after the fact but assessed before the fact without knowing whether one would actually benefit or suffer from it.
This approach follows the " veil of ignorance" approach, which was first proposed by John Harsanyi but popularized by John Rawls in his 1971 Theory of Justice. Historically, however, the approach can be traced to John Stuart Mill, who, in his letter to George Grote, explained that "human happiness, even one's own, is in general more successfully pursued by acting on general rules, than by measuring the consequences of each act; and this is still more the case with the general happiness, since any other plan would not only leave everybody uncertain what to expect, but would involve perpetual quarrelling..."
The Institute of Chartered Accountants in England and Wales argues that applying a detailed definition is likely to result in unintended consequences, in Acting in the Public Interest(2012). Instead, each circumstance needs to be assessed based on criteria such as the relevant public, wants, and constraints. The key to assessing any public interest decision is transparency of the decision-making process, including balancing competing interests.
Usage examples of "public interest".
When Xenia had been born such a spectacle, a supernova a mere nine thousand light-years away, would have been a source of great scientific and public interest.
Years of progress on Earth and major expeditions in the interstellar reaches of the universe caused public interest in Venus and its fortress to somewhat wane.
And, in the public interest, won't you release me from the promise?
And then, just as public interest was beginning to die down, a startling development occurred: Madame Beroldy was arrested and charged with the murder of her husband.
In any event, I deem your activities mischievous, and contrary to the public interest.
On the afternoon of a certain fine Sunday when the waves of four months had rolled over the trial for treason, and carried it, as to the public interest and memory, far out to sea, Mr.
Then three or four western bad men aspired to clean out the town, were riddled like pepper-boxes for their pains, and public interest turned to other idols.
Gross, who was supposed to guard the public interest, seemed to have gone to sleep in a chair.