How much can Google Ngrams really tell us about history?

And then there’s the idea that oscillations in the Ngram graphs say something meaningful about the collective mood of a country. Acerbi told Nature magazine that “just by doing a somewhat crude analysis of emotion words it is possible to find trends that resonate with what we know about history.” Confirmation bias alert! Certainly, it is possible to cherry-pick historical events that support a particular reading of a line’s peaks and dips. Whether those events actually explain the ebb and flow of moody words through the years is far from certain. (The researchers even noted that the World War I era didn’t see the expected rise in mournful terms.) 

It seems like there may be some similar cherry-picking happening in a new paper by George Mason University economist Daniel Klein:

In this very casual paper, I reproduce results from the Google Ngram Viewer. The main thrust is to show that around 1880 governmentalization of society and culture began to set in – a great transformation, as Karl Polanyi called it. But that great transformation came as a reaction to liberalism, the first great transformation. The Ngrams shown include liberty, constitutional liberty, faith, eternity, God, social gospel, college professors, psychology, economics, sociology, anthropology, political science, criminology, new liberalism, old liberalism, public school system, Pledge of Allegiance, income tax, government control, run the country, lead the country, lead the nation, national unity, priorities, social justice, equal opportunity, economic inequality, forced to work, living wage, social needs, our society, bundle of rights, property rights, capitalism, right-wing, left-wing, virtue, wisdom, prudence, benevolence, diligence, fortitude, propriety, ought, good conduct, bad conduct, good works, evil, sentiments, impartial, objective, subjective, normative, values, preferences, beliefs, and information.

First of all, the longterm decline of the word “liberty” probably has more to do with the fact that people now more commonly use “freedom” to refer to the same thing, a trend that was noted by the Atlantic’s Alexis Madrigal back on 2010: