The 10 most popular Brookings pieces of 2015

As 2015 comes to a close, we reflect on the more than 4,000 pieces of content authored by over 200 scholars on hundreds of topics to select ten of the most popular of the year.

The Believer: How Abu Bakr al-Baghdadi became leader of the Islamic State

Will McCants, in this Brookings Essay, traces the rise of an introvert with a passion for religion and soccer to the head of a self-proclaimed caliphate.

Beyond College Rankings

Jonathan Rothwell and Siddharth Kulkarni analyze college “value-added,” the difference between actual alumni outcomes (like salaries) and the outcomes one would expect given a student’s characteristics and the type of institution.

Why are interest rates so low?

Ben Bernanke says that low interest rates are not a short-term aberration, but part of a long-term trend.

The Prince of Counterterrorism: a profile of Saudi Prince Muhammad bin Nayef

Bruce Riedel, in this Brookings Essay, calls Muhammad bin Nayef “Washington’s favorite Saudi” for his efforts to fight al-Qaida, but cautions that he is no friend to those who seek reform in his kingdom.

U.S. Army size and defense expenditures relative to other nations

Is the U.S. military too large, and costly? The chart from Michael O’Hanlon’s new book, “The Future of Land Warfare,” shows that while the overall U.S. military budget outstrips the rest of the world, the relative size of the United States Army does not.

Changing Face of the Heartland

In her Brookings Essay, Jennifer Bradley showed how metropolitan areas like the Twin Cities in Minnesota need to be preparing for an increasingly diverse workforce.

Measuring Obama against the great presidents

Presidents Day is often a time to reflect on our greatest leaders, and consider how our current commander-in-chief measures up. On that occasion this year, Brandon Rottinghaus and Justin Vaughn reviewed old and new evidence on presidential greatness.

Diversity Explosion: The cultural generation gap mapped

This interactive feature, based on William Frey’s work in “Diversity Explosion: How New Racial Demographics are Remaking America,” mapped the racial composition of different age groups at the county and metropolitan area scales.

The typical male U.S. worker earned less in 2014 than in 1973

The median male worker who was employed year-round and full time earned less in 2014 than a similarly situated worker earned four decades ago, observed David Wessel. And those are the ones who had jobs.

12 things we know (and don’t know) about Bernie Sanders’s marijuana proposal

Democratic presidential candidate Bernie Sanders announced a proposal to dramatically shift U.S. marijuana policy by removing marijuana from the Schedule of Controlled Substances entirely. John Hudak breaks down what we know, and what we don’t know, about the impact of this proposal.