We made ratings less important because the implicit signal of your behavior is more important - Todd Yellin, Netflix VP of Product
This laser-focused personalisation should help to dispel some of the knottier aspects of Netflix’s current rating system, like the annoying virtue-signalling quirk where users give higher ratings to important eat-your-vegetables documentaries than the dumb Adam Sandler movies they watch over and over again. - Stuart Heritage, Does Netflix changing its rating system matter? No, because people are still awful
However, over time, Netflix realized that explicit star ratings were less relevant than other signals. Users would rate documentaries with 5 stars, and silly movies with just 3 stars, but still watch silly movies more often than those high-rated documentaries. - Janko Roettgers, Netflix Replacing Star Ratings With Thumbs Ups and Thumbs Downs
Basically Netflix had the incredible epiphany that actions (what people watch) speak louder than words (what people highly rate). Netflix finally got the memo that talk is cheap.
Virtue signalling really isn't a new thing...
The people feeling, during the continuance of the war, the complete burden of it, would soon grow weary of it, and government, in order to humour them, would not be under the necessity of carrying it on longer than it was necessary to do so. The foresight of the heavy and unavoidable burdens of war would hinder the people from wantonly calling for it when there was no real or solid interest to fight for. - Adam Smith, Wealth of Nations
They will not indeed submit to more labours and privations than other people, for the relief of distressed fellow creatures: but they make amends by whining over them more. It is not difficult to trace this sort of affectation to its cause. It originates in the common practice of bestowing upon feelings that praise which actions alone can deserve. By properly regulating his actions, a man becomes a blessing to his species. His mere feelings are a matter of consummate indifference to them. And who will say that praise is well bestowed on that which by no possibility can be of any use whatever? Not to mention that nothing is so easily counterfeited as feeling, and that the most intense demonstrations of it are not inconsistent with the total absence of the reality; what can be more absurd than to praise a man because he has a feeling; to praise him because he has something which he can no more help having, than he can help having ten fingers, or two feet, and which, for any good which it does, he might as well not have at all. The effect is, to create fictitious virtues, and thus to hold out the means of atonement for the absence of real ones; to render it possible, nay easy, to obtain a reputation for virtue, without the trouble of deserving it. Whether this is likely to give any great encouragement to real virtue, is a question which we may fairly leave it to the reader to determine. - J.S. Mill, Periodical Literature: Edinburgh Review
As was noted in Chapter 3, expressions of malice and/or envy no less than expressions of altruism are cheaper in the voting booth than in the market. A German voter who in 1933 cast a ballot for Hitler was able to indulge his antisemitic sentiments at much less cost than she would have borne by organizing a pogrom. - Loren Lomasky, Geoffrey Brennan, Democracy and Decision
In technical terms... star ratings and thumbs up/down ratings are known as contingent valuation (CV) techniques...
Economists have attempted to assign economic values (based on the principle of substitutability at the margin) to noncommodity items by methods such as shadow pricing and contingent valuation surveys. These methods are plagued with problems of accuracy and legitimacy. - Paul M. Wood, Biodiversity and Democracy
In addition to CV surveys eliciting apparently inconsistent responses, some researchers question whether survey subjects are attempting to state their true demand for public goods. The worry is not that survey takers will strategically disguise their preferences (since little can be gained by giving false answers to questions about non-binding projects), but rather that they may be doing something else all together. For example, Diamond and Hausman (1994) suggest that respondents may be expressing an attitude that gives them a warm glow, even if they wouldn't be willing to support their response to a hypothetical question with actual money; or they may be describing what they think good citizens are supposed to say, rather than calculating how much benefit they would derive, all things considered, from allocating a specific amount to a particular good. - Jonny Anomaly, Public Goods and Government Action
If people's Netflix ratings are untrustworthy, then what does that say about democracy? How confident should we be that Trump accurately reflects the true will of the people?
Personally, I don't spend very much time on Netflix watching shows about economics. Instead, I spend far more time watching anime. Anybody else love One Punch Man? So according to my actions I love anime a lot more than I love economics. Actually no. The fact of the matter is that Netflix has a severe scarcity of shows about economics. It's not like I can spend a lot of time watching shows that don't exist! If only there was a system that would allow me to easily, quickly, effectively and accurately communicate my perception of some content's relative scarcity...