On Tuesday, we looked at the relative popularity of Major League Baseball teams as based on Google searches. That resulted in the following chart:The Yankees and Red Sox are popular? Quelle surprise! Nonetheless, sources such as Google and Facebook give us access to new types of data on fandom and provide a little more precision than the conventional wisdom.We’ve also run the numbers for the NBA, NHL, NFL and English Premier League. This data can tell us something not only about which teams are most popular, but also about the structure of sports leagues. The ground rules were the same as for our baseball figures:The data is taken from Google Trends and is based on searches worldwide for each team since 2004. The exceptions are expansion teams or relocated franchises, when the data is run from the team’s first month of operation in its new location.Google organizes individual search strings into topics — for instance, “NY Rangers” and “rangers hockey” should be counted as searches for “New York Rangers.” The process is undoubtedly imperfect, but it works well in most cases (for example, “New Orleans Hornets” seems to transition seamlessly into “New Orleans Pelicans”).All figures are taken relative to the league average; a score of 1.00 represents a team with league-average popularity.Here’s the data for the NBA:It’s not surprising to see the Lakers on top, but the extent to which they lap the field is striking: The Lakers are about as popular as the Knicks and Heat combined. (Keep in mind that this data dates back 10 years. In the past 12 months, during which time the Lakers have stunk, the Heat have been searched far more often.)But overall — despite the NBA’s reputation for being a league of superstar players and dominant franchises — the distribution between the haves and have-nots is not that different than in baseball. In the NBA, the 90th percentile team is searched for 5.3 times more often than the 10th percentile team; in MLB, the ratio is 4.0 instead. This may reflect the fact that the correlation between market size and team success has been extremely low in the NBA. (The Knicks can blow up the Internet when they do well, but they usually don’t do well.) In baseball, by contrast, the most successful teams tend to play in bigger markets, with both factors contributing to their popularity.Next up is the NHL:As FiveThirtyEight has written, Canadian NHL teams (which we’ve highlighted in the chart) are disproportionately popular. The Edmonton television market is only about one-fourth the size of the Dallas market, but the Oilers generate more than twice as much Google activity as the Stars. (Neither team has been much good over the past several seasons, so this would seem to reflect hockey’s intrinsically higher popularity in Canada.) Bring back the Nordiques!The NFL has a reputation for parity because of its strict salary cap, revenue-sharing rules and a short schedule that has teams vaulting up and down the standings every season. This parity is also reflected in its Google data:The Cowboys are the NFL’s most popular team. But they are searched for only 2.4 times as often as the league average — not as disproportionate a ratio as the Canadiens (2.9), Yankees (3.8) or Lakers (4.5) in the other sports. Meanwhile, only one NFL team — the Jaguars — has a popularity rating of 0.4 or below; that compares with six in the NBA and the NHL, and four in baseball.What about a notoriously inequal league: the English Premiership? Since the Premier League was founded in 1992, three clubs — Manchester United, Arsenal and Chelsea — have won 19 of its 21 championships. Those clubs and a fourth, Liverpool, also account for 70 percent of Google searches. Manchester United alone is as popular as the bottom 14 teams in the Premiership combined.Our data, incidentally, only reflects searches from those seasons in which a team actually played in the Premiership (rather than a lower division); otherwise the gap between the most and least popular teams would be even greater. But there is very little resembling a middle class in English football, with the possible exception of Tottenham Hotspur.One of us (Nate) has said that American sports leagues are socialist and European sports leagues are capitalist. It’s only a modest exaggeration.Economists use something called the Gini coefficient to measure inequality within a country. A maximally equal country (where everyone has exactly the same amount of wealth) would have a Gini coefficient of 0.00. A maximally unequal country (one person has all the money) would have a Gini coefficient of 1.00. In practice, countries range from 0.23 (Sweden) to 0.63 (Lesotho) on this scale, as based on the CIA’s World Factbook.The sports leagues we’ve studied occupy nearly as wide a range. The NFL’s Gini coefficient, based on the distribution of Google searches for each team, is 0.27. That’s similar to Sweden, Finland (0.27), Germany (0.27) and Iceland (0.28), countries with high rates of taxation and government spending.The Premier League’s Gini coefficient is 0.60, much like Lesotho, Sierra Leone (0.63) or Haiti (0.59), whose economies are extremely unequal and verge on being anarchic. The NBA (0.41), NHL (0.38) and baseball (0.36) fall in a middle range, somewhere between the United States (0.45) and Canada (0.32) on the spectrum.