This post has been updated to reflect that the Open Syllabus Project database algorithms can’t determine when texts with single-word titles and no specified author, such as the Bible, are included in syllabi.

More than 25 years after the fall of the Berlin Wall, the collapse of the Soviet Union and the onset of market-economy practices in China, “The Communist Manifesto” still ranks among the three most frequently assigned texts at American universities.

That’s according to data from Open Syllabus Project, which tracks books and other works assigned to students in more than 1 million syllabi.

The database is assembled using computer algorithms that scrape the data from publicly available sites. It is still very much a work in progress, according to its website and project leader Joe Karaganis. The syllabi analyzed are primarily from the U.S. and cover the past decade or so.

Each text is assigned a count, registering the number of times it appears in syllabi, and a teaching score, “a numerical indicator of the frequency with which a particular work is taught,” according to the site.

A number of notable works, including the Bible and the U.S. Constitution, don’t appear in the data set. “The Bible’s one of a number of prominent texts we can’t say anything about,” said Karaganis, vice president of the American Assembly at Columbia University. That’s because the computer algorithms used to compile the data can’t handle single word titles by unspecified authors.

In addition, while the database has analyzed more than 1 million syllabi, the group estimates that there are more than 80 million that could be reviewed. The data include syllabi from all levels, ranging from community colleges to Ivy League schools, Karaganis said.

Some books show up where you might not expect them.

For instance, a search for “economics” shows Paul Krugman at the top of the list with his iconic “Economics,” which gets a count of 1,081 and score of 89.4. However, Gregory Mankiw’s “Macroeconomics” doesn’t appear at all under the same search, even though it gets a count of 989 and a teaching score of 87.5.

Karl Marx’s classic receives a count of 3,189 and a score of 99.7. It doesn’t actually show up under economics texts, either, as it is generally taught along with philosophy texts such as “The Social Contract,” by Jean-Jacques Rousseau; “Leviathan,” by Thomas Hobbes; and “On Liberty,” by John Stuart Mill. “’The Communist Manifesto’” is widely taught as a work of social theory,” rather than as an economics text, Karaganis said. He added that when Marx is taught in economics classes, professors generally assign “Capital” (or “Das Kapital”), which received a count of 1,447 and a score of 94.6.

The only books assigned more frequently than “The Communist Manifesto” were “The Elements of Style,” the writing guide by William Strunk, popularized by E.B. White, and “The Republic,” by Plato.

Among other standouts, “Mein Kampf,” by Adolph Hitler, received a count of 697 and a score of 75.7. “What Is To Be Done,” by Vladimir Lenin, received a count of 361 and a teaching score of 45.9.

Here’s a look at the most frequently taught works by notable economists (and others) relating to economics and money: