It’s Christmas time, and for millions of families around the country, that means revisiting some classic holiday movies. For some, that includes It’s a Wonderful Life and Home Alone. For others, that includes Die Hard. In this analyst’s view, Die Hard is a Christmas movie, though this is not an institutional position of Tax Foundation. And disclaimer: this post will contain spoilers for Die Hard if you have waited over 30 years to watch it and do not want to ruin a Christmas classic.

So, what could Die Hard have to do with taxes? Well, if you’re like me, somewhere around your dozenth time watching the movie, you began to wonder about Hans Gruber (played by Alan Rickman) and the details of his planned heist of the fictional Nakatomi Corporation.

For those in need of a refresher, it’s 1988, and Hans Gruber develops a cover as a German extremist and takes several employees of the Nakatomi Corporation hostage. He then makes a series of demands, both for political concessions and transportation, while beating back official efforts to liberate the hostages. Of course, Gruber is not really an ideologue—he’s a common thief, or perhaps an exceptional thief if you ask him. Gruber will use various aspects of the government’s response to access the Nakatomi Corporation’s vault—and its $640 million in bearer bonds—abscond with the loot, destroy the building, and disappear, knowing he will be presumed dead in the rubble.

And he would have gotten away with it too, if it were not for that fly-in-the-ointment, monkey-in-the-wrench, off-duty New York cop John McClane. But one part of the plan confused me: the bearer bonds. What is a bearer bond? It’s not a type of bond one often hears discussed today. Why had I never heard of bearer bonds before?

Taxes.

To raise capital, one option for firms and governments is to sell bonds, paying interest to creditors who purchase the bonds. Historically, bonds were sold with a physical certificate that came with physical coupons representing interest payments owed. Bearer bonds included these physical coupons, which proved to be a useful tool for illicit activities because they were effectively anonymous. The issuer kept no record of who owned the bond; the coupon holder would just take coupons to a bank location to cash out.

The Tax Equity and Fiscal Responsibility Act of 1982 (TEFRA) prevented issuers of bearer bonds from deducting interest costs from taxable income. It also required issuers of bearer bonds to pay an excise tax of 1 percent on the principal value of the bond, multiplied by the bond’s length of maturity. In other words, if a company issues $1 million in bearer bonds that would mature in 10 years, they owe $100,000 in excise tax liability upfront, and they will not be able to deduct interest payments for the life of the bond.

TEFRA raised the after-tax cost of raising money through bearer bonds relative to the cost of raising money through the alternative: registered bonds. When companies issue registered bonds, they keep track of the owner, making them much less vulnerable to schemes like Mr. Gruber’s.

Now, is it a plot hole in Die Hard (a movie from 1988) that the Nakatomi Corporation still has hundreds of millions of dollars in bearer bonds, even though TEFRA was passed in 1982? Not necessarily. While new issuances of bearer bonds effectively ended following TEFRA, making them a “disappearing breed,” as The New York Times observed in 1984, securities issued before 1982 would have still been in use. Additionally, bearer bonds still exist in some foreign markets.

Die Hard is not the only piece of American pop culture that prominently features bearer bonds. The Wall Street Journal wrote in 2015 that bearer bonds also appear in F. Scott Fitzgerald’s The Great Gatsby. But in the United States today, they are mostly a historical artifact—in large part due to one little-known tax change.

So, go out to the coast, get together, have a few laughs. Merry Christmas to all, and to all a good night.