Titanic, James Cameron's epic film about the massiveness of boats, luxury, hubris, and teen love, celebrates its 20-year anniversary today. This weekend will also see the premiere of Downsizing, Alexander Payne's sci-fi comedy about a world in which Americans who want a better life will literally shrink themselves down in order to get it.

The contrast is telling. Titanic was in part about how technological progress metastasizes into a tribute to greed and luxury doomed by virtue of its mammoth size. Downsizing is about how a technology intended to help save the world by shrinking human consumers (so they're a mere five inches tall) turned into the ultimate explosion in consumerism. Both films deal with luxury's inherent problem: that you need an underclass to power it and a coercive system that forces them aboard. And both ask the same basic question: What parts of yourself will you sacrifice in order to feel rich?

The premise of Payne's Downsizing is fascinating and straightforward. If Norwegians developed an ecological solution to humanity's disastrous, world-threatening carbon footprint, Americans turned that into a way to stretch a dollar by shrinking themselves. Matt Damon plays Paul Safranek, a therapist who decides (along with his wife, played by Kristin Wiig) that they have so little to look forward to as full-sized humans that they take the plunge. They'll shrink themselves in order to live in a pint-sized luxury gated community (where the grass really is greener!) presided over by Christoph Waltz. It's a parody of the American obsession with relative wealth: Why not decamp from the existing system whose comparative metrics you'll never beat to one where you're the one people are keeping up with?

There's a limit to how much movies reflect their moment in history, but the parallels between America's romantic ode to empire's doomed gigantism and its comedy about shrinkage speaks to the evolution of our national mood. Titanic premiered on the early side of the dot-com bubble — when it seemed like unlimited growth was inevitable and even sustainable — while Downsizing comes to us as U.S. housing bubbles multiply while affordable housing has decreased by 60 percent in a mere six years. America is a hodgepodge of hurricanes and fires, and everyone is saddled with debt. Given these constraints, how does fantasy change?

The difference is reflected, in part, in the two films' radically different attitudes to cost. Titanic was an ode to human consumption. The point was its vast and purely decorative expense, a point made in miniature by the necklace Cal "gives" Rose. Downsizing, which opens in a resolutely middle class POV, is an ode to making every cent count: The appeal of the luxury on offer at Leisureland is that it's cheap. (You just have to give up your size, the space you take up in the world, and your ability to socialize as equals with the community that doesn't transition.) And even the fantasy isn't "real" luxury but rather a tiny version of the knockoff version, the giant McMansion. Titanic burned money, tossed it into the ocean, sank it into the sea. Downsizing measures each expense.

As in Titanic, the pleasure of Downsizing is partly the contrast in visual scale: It's the sheer thrill of watching very big things next to very small things. As in Titanic, the protagonist of Downsizing's relatively privileged concerns are altered — and their worldview expanded — by a friendship with someone's who's suffered greater hardships, and who gives them insight into how the "other half" lives. But what's telling about the difference between the movies opening in theaters in December 1997 and December 2017 is how Downsizing both satirizes and literalizes what people are willing to give up to feel, ahem, "economically secure." (And if you don't see the metaphor here, I'm not sure what to tell you.)

If Titanic explores the downside of being huge, Downsizing explores the potential in being small. The point of the RMS Titanic was to make something so enormous that humans would look puny in comparison to the wasteful greatness of their species' achievement. (In practice, it created an expensive, symbolically vacuous death trap that killed its creators.) Downsizing imagines pint-sized humans gazing up in consternation at their former stature (and hubris). It ponders the comparative moderation of our fantasies and the rapidity with which even they collapse, as a technology that could save the world gets instantly co-opted into a recipe for tiny reproductions of the emptiest versions of wealth and worst reproductions of poverty.

Even our miniature bubbles are sad. We're tiny, even compared to what we once were. But this is also a journey from tragedy to comedy, and maybe, in taking the full measure of our smallness, there's a little clarity (and even hope).