Readers and posters here seem to be concerned with whether predeterminer half used with a plural Noun Phrase should be regarded as singular or plural.I thought some hard talking facts might be in order to resolve this issue.
A Google search for:
"over half the people was"
... with the phrase in quotation marks as in the example, returned a staggering three hits! Two of these were along the lines of "the average age of over half the people was 2.14..." So that reduces it to one valid hit of the type with which we're concerned here.
On the other hand the same search for:
"over half the people were"
... gives a return of 245, 000 results. Now on the basis that grammar is what people actually do when they speak, this means that Over half the people were is 245,000,000 % more likely to be grammatical than Over half the people is.
If further evidence is required, the number of instances of Over half the people were from Google books is 2,100. The number of instances of Over half the people was, surprisingly, is 1. However, this single example on close inspection turns out to be in the form of the following:
The standard of living for over half the people was beneath what would have been considered enough for an animal in France or England.
Here the subject of was is the non-countable Noun Phrase standard of living. This reassuringly puts the number of published examples of Over half the people was - specifically of the type we're after - at zero.
So purely on an empirical basis, we can discard any notion of Over half the people grammatically occurring with a singular verb form! Full stop. Over and out!
[However, there is an interesting side story here because of the the existential sentence in the OP's question. It used to be, and to a certain extent still is, common to find existential "there was" used with a following plural Noun Phrase. Thousand upon thousand of such examples are to be found in print and even in scholarly works.]