— Hillary Rodham Clinton (D), speech on criminal justice at Columbia University, April 29, 2015

“Though only five percent of the world’s population lives in the United States, it is home to 25 percent of the world’s prison population. … Not only does the current overpopulated, underfunded system hurt those incarcerated, it also digs deeper into the pockets of taxpaying Americans.”

— Sen. Rand Paul (R-Ky.), news release on Web site, March 9, 2015

During Clinton’s recent speech on criminal justice, she cited a widely quoted statistic about the share of prisoners in the United States compared to other countries. As shown above, she is not the only 2016 presidential candidate to have used this comparison. Paul, in his criminal justice proposals with Sen. Cory Booker (D-N.J.), also uses this figure.

These two politicians are among countless others who have used this statistic for several years. Yet it sounds dubious and disproportionate. Is it accurate that the U.S. accounts for about 5 percent of the world population, but about 25 percent of the world’s prison population?

The Facts

The United States population was 319 million as of July 4, 2014, according to the U.S. Census. That accounts for about 4.4 percent of the approximately 7.1 billion world population, which confirms the first part of this claim.

The second part comes from the World Prison Population List, published by the U.K.-based International Centre for Prison Studies. It is considered the go-to source for the breakdown of global prison populations. The most recent report, the 10th edition, used data from 222 countries from September 2011 through September 2013.

There were 2.24 million prisoners in the United States as of Dec. 31, 2011. That accounted for about 22 percent of the global prison population (10.2 million). About half of the prisoners in the world were in the United States, Russia or China.

So the numbers check out, give or take a few percentage points. (Clinton, we should note, was careful to say “less than five percent” and “almost 25 percent.”)

Critics who advocate stricter sentencing laws say this list overlooks cultural factors influencing imprisonment, and is incomplete because countries like North Korea, China and Iran may downplay their figures.

Indeed, the report says its numbers are not complete, especially for China. The most recent report does not include figures for Eritrea, Guinea Bissau, Somalia and North Korea. It acknowledges difficulties comparing countries; there are different practices for housing pre-trial detainees, juveniles and offenders with mental illnesses or drug addictions. Some repressive countries with more violent police forces may have fewer people who are tried, convicted and imprisoned, and more people beaten or killed on the street.

Researchers wrote that they hope the list will help policymakers and experts to place into context the size and cost of the prison population in their country.

The numbers are more startling using a different measure in the report: the prison population rate. Criminologists say this is a reliable way to compare incarceration practices between countries.

The United States had the highest prison population rate in the world, at 716 per 100,000 people. More than half of the countries and territories had rates below 150 per 100,000. The United States had a much higher rate compared to other developed countries: about six times Canada’s rate, between six to nine times Western European countries, and between two to 10 times Northern European countries.

Decades ago, the United States’s prison systems set a model for European countries. Then the U.S. trends reversed, and incarceration rates soared. Many factors led to this increase, said experts who advocate overhauling the criminal justice and sentencing system.

Public policies enacted in the 1970s through the 1990s led to stricter federal sentencing laws, more enforcement and more imprisonment. Mandatory sentencing laws also contributed to longer sentences. These policies were intended to reduce crime by keeping people behind bars, or deterring them from crime through the possibility of lengthy prison terms. Prison also became a means to treat a host of mental and physical health issues and drug abuse, said Inimai Chettiar, director of the Brennan Center for Justice at the New York University School of Law.

Consider this graphic from FiveThirtyEight:

In recent years, more states have decided to move away from the “get-tough-on-crime” approach. Instead, states are trying to reduce prison population, reclassifying high- and low-risk offenders, and using community-based resources for lower-risk offenders.

Marc Mauer, executive director of the Sentencing Project, noted that the unprecedented rise in prisoners over four decades has been a function of changes in policy, and not crime rates. An analysis of FBI data, published by the Pew Charitable Trusts, found that crime and imprisonment rates decreased between 2008 to 2013. (The Fact Checker dug further into this issue in January 2015.)

The Pinocchio Test

This is an example of figures that sound so dramatic that they sound unbelievable. However, the go-to report of world prison populations confirms the figures. Despite its caveats, the list is the definitive global prisoner count and researchers have refined their method over the years.

It would be helpful for candidates to cite another figure from the same report while using this comparison. The U.S. prison population rate in comparison to other countries is a powerful and reliable measure, and still makes the same point. Nonetheless, the comparison used by Clinton, Paul and others earns the elusive Geppetto Checkmark.

The Geppetto Checkmark

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