It is impossible, this time of year, not to assume that all Americans are idiots, throwing billions of dollars at movie studios for producing terrible movies meant to numb us into becoming drooling popcorn-digesters. But that's not entirely the case! We looked at nearly 800 movies from the past four years, and learned that America actually does spend money on good movies!*

(We'll get to that asterisk in a bit.)

To figure out the relationship between quality and cash, we looked at the top-grossing 200 movies for the past four years. For each of those movies, 797 in total once we removed some outliers, we looked at the first weekend earnings, how many theaters it ran in, and overall earnings (via BoxOfficeMojo.com) and the average critic ratings (via, of course, Rotten Tomatoes). Then we took that data and made graphs.

We're going to tease you with this one. It shows the first weekend, per-theater earnings of movies in five groupings, from lowest tier of Rotten Tomato rankings at left (the worst movies) to highest tier (best movies) at right. And, voila. Americans spend more money on better movies. If you thought that marketplace for movies doesn't reward quality, you were wrong. * ** *** (And more asterisks to come.)

The first qualification of that graph comes from a more detailed look at the data. Let's start with gross earnings — how much each of our movies made, in total, since release. A quick bit of explanation on these charts is in order. The horizontal x-axis on each of the blue charts shows Rotten Tomatoes rating which, if you're not familiar, is a percentage of critics' ratings. A 100 means every review was positive; a 50, the reviews were mixed; a zero, everyone hated the film. The vertical y-axis shows earnings. So a dot at the upper left of a graph earned a lot of money but was a poorly reviewed movie.

This is clearly not as definitive as that first graph. If our hypothesis is that crappier movies earn more money, though, this is at least some indication that it's not true. The right (better movie) side of the chart has more movies earning more money. But there are a lot of movies in that thick cluster at the bottom of the graph that suggests the numbers might not be as clear as they at first seemed.

If anything, we've added an element of doubt. So next we looked at debut weekends. After all, how a movie premieres is a huge predictor in its longevity. Here are first weekend totals. As you can see, far more crappy movies — Twilight Saga — had big first weekends than overall totals. (Again, The Avengers floats up to the top.)

Here again, though, there's a qualifying factor. Big movies debut in more theaters, which often means bigger receipts. A movie that grossed $10 million running in one theater for a weekend is probably better than a movie that earns $20 million running in 100 theaters. But, on the other hand, finding 4,253 theaters in which to open Iron Man 3 means booking a lot of theaters that might not get a lot of traffic (or even seat that many people).

Nonetheless, the graph is suggestive. There is a giant stack of movies in the 75 percent-plus rating range that doesn't exist for worse films. We also see Twilight sink — too many theaters.

Another asterisk: Air Racers 3D doesn't have enough critic ratings to earn a Rotten Tomatoes score. In situations like that, we gave the film a mid-range 50.

Back in our original graph, opening weekend box office followed the critics ratings pretty consistently. But for total earnings, with the left axis in millions, the chart look very, very different.

What can we learn from these graphs? Apparently more people fill theaters for good movies when they first come out — but then later on go watch a lot more junk. Apparently. That's not the only issue.

Rotten Tomatoes ranks movies as good (or, in their verbiage, "fresh") with a ranking of 60 percent or higher. Movies below that level are "rotten." Fine. But here's the distribution of all 797 of the movies, by year and ranking. There are more 50 percent films both because of our assigning that value to unranked movies and because 50 percent comes up more in the math: four of eight reviews, six of twelve.

You may notice that the graph is a little heavier on the right side of that middle point. In fact, here's the distribution by year. Over the four-year spread, ratings have gotten better — perhaps because the movies are, but that seems debatable.

Here are the median ratings for each year. At left is the overall median ranking — 58. Meaning that the graph above showing that we are more likely to go see good movies that first weekend is a bit warped by the fact that more of these movies are "good."

One possible reason for this is that we only took the 200 highest-grossing movies from each year. Really terrible movies probably wouldn't get into that cut. But even with that criterion, each year included a number of movies that we'd never heard of. (Kings Faith? Nowhere Boy?)

There's another possibility. Prestige films, ones critics love, are more likely to open in a smaller number of theaters, often in markets like New York and L.A. which have high-grossing theaters.

Fewer theaters, especially if they're the biggest theaters in the country, means a higher likelihood that a good film can fill those seats — meaning more money per theater. Particularly if it's opening weekend, right after those critics' reviews have come out.

So we're left with one moral. If you're going to see a movie when it opens, you're probably making a better decision than the ones you see that have been out for a few weeks. But when it comes down to it, people are little more than inscrutable popcorn-digesters.