In practice, election results are determined by a complex system of laws and rules that vary from country to country. This means that polling data is only a partial picture of what actually happened. In order to be accurate, it is necessary to combine information from different sources. The use of these data requires a degree of expertise, and the results can be difficult to interpret.
In addition, the process of determining a winner includes a step known as a canvass, in which elections officials examine all of the ballots to ensure they have counted every vote and that there are no clerical errors. This can take days, and is the only way to know who really won.
These factors mean that the results reported on election night are never final and certified. But many voters look to elections officials for trusted information about results, and how they communicate those results can play a role in establishing public confidence in the process.
In the United States, the result of a tight race can have significant ramifications for the economy and global geopolitics. Johns Hopkins Carey Business School scholars have analyzed the impact of a Kamala Harris or Donald Trump presidency on seven key policy areas.