When we’re writing or — especially — speaking, it’s so much easier for us to avoid looking up actual statistics we’re talking about. Instead, we often (see how I’m not quoting a frequency?) just use words like “a lot”, “often”, most”, “many”, and so forth. By itself, this isn’t a bad thing: we’d never have enough time in the day to constantly look up all of the statistics we’d need. But they do cause problems.
You see, it’s easy to abuse this words as weasel words, phrases we throw in not to simplify our lives but to give a mistaken impression while maintaining dependability. If I say something like, “a lot of people want X,” you would probably walk away thinking there’s a large percentage of people who want that. But really, what does “a lot” mean? More than 5? 10? 100? 1000? A thousand people is, by most standards, “a lot”, after all. I wouldn’t want that many in my class, for example. But for national politics, it’s a tiny number. Of course, if you called me on my statement, I could just hide behind the ambiguity of the phrase, “a lot”.
I’m not saying you should question the exact stats every time you encounter these phrases. But certainly when reading (or listening to) formal communication, be it a corporate memo or an op-ed, it’s worth asking what the values actually are and why the writer/speaker didn’t give them to you. Did he not know/couldn’t be bothered to check? Did she want to hide them? Or did the stats just not exist? (In which case, how appropriate is the quantifier at all?)