Click here for a full-size version of this week’s map.

This map is a choropleth of the countries of the world. (Do you need a refresher on what a choropleth is? Visit our “Basics” page for a quick primer.) On this map, darker shades of purple indicate countries with more of a particular statistic. There are also several countries that appear grey on this map because we do not have accurate data for them; you should ignore these countries. Usually, when we make choropleths, we try to follow a linear scale in which each color corresponds to the same range of values. In this case, however, we have mapped a very wide range of values, so we have used a slightly more complicated scale. Essentially, all you need to know about it in order to make sense of this map is that the countries in the darkest colors have many, many more times the value of this week’s statistic than do the countries in the lightest colors. We also want to warn you from the outset this week to try to be fairly specific with the wording of your solutions. Your job for this week: figure out what statistic is represented by this choropleth.

Stumped? Check back Tuesday, Wednesday, Thursday, and Friday for hints about where to focus your investigation. The answer will be posted on Monday, February 6. Good luck!

Tuesday’s hint: First, let’s take a look at South America. Most countries here are fairly light. You can go ahead and ignore French Guiana, which is legally part of France and thus has taken on the same color as the rest of France. The only countries on the continent which really stand out are Venezuela and Ecuador. These two countries, along with nearby Panama, have something important in common. If you can figure out what that is, you’ll be one step closer to making sense of this choropleth.

Wednesday’s hint: On this map, most countries in the developed world, including the United States, are fairly light. Among the exceptions to this trend are a few countries in Europe that are moderately dark, including Sweden, Norway, and Switzerland. Our suggestion to help you solve this map is to read up on recent Swedish politics—doing so just might give you some ideas that will put you on the right track.

Thursday’s hint: One of the unfortunate features of this map is that the third darkest country is too small to be seen. Nauru, a tiny country in the Pacific Ocean, has an entire shade of purple to itself—lighter only than Lebanon and Jordan. Alas, it only accounts for about a single pixel so you can’t see it. Although people often don’t pay much attention to Nauru, it has been in the news this week in conjunction with another big story. Yesterday, American President Donald Trump abruptly ended what was supposed to be a much longer phone conversation with Australian Prime Minister Malcolm Turnbull. If you can figure out how Nauru fits into this conversation, that discovery may lead you to the solution to this week’s map.

Friday’s hint: On Tuesday, we asked you what Venezuela, Ecuador, and Panama have in common. The answer is that all three of those countries border Colombia. It is possible to look around this map and find several examples of countries that have several neighbors colored in fairly dark purple. In Africa, you might notice that Mali, Central African Republic, and Somalia are all conspicuously lighter than their neighbors, just like Colombia is in South America. But perhaps the most important example of this phenomenon is Syria, which is dramatically lighter than Lebanon, Jordan, and Turkey. What kind of relationship does Syria have with its neighbors right now? What would you be likely to find if you visited Lebanon, Jordan, or Turkey—especially the parts of those countries nearest to their borders with Syria?

Answer: Click here to see an explanation of the answer to this week’s map question.

Next map: Click here to try out our newest map question.