Newmark's Door

I think it's interesting that in a universe of 14.2 million blogs, three of the top 200 are economics blogs. Is that more than we'd expect, or less? And I'll note immodestly that the top two link here, to the Door.

Ranking 2 uses information from The Truth Laid Bare. TTLB is a well-known and well-respected source of blog rankings. In last week's Washington Post article on political blogs, featuring my wife, David von Drehle cited TTLB rankings.

Where "n/a" signifies "not available". 

I think the amount of agreement between the BlogPulse rankings and the TTLB--Link rankings is reasonable, with a couple of exceptions. Both Mahalanobis and The Eclectic Economist rank a bit better according to BlogPulse. I don't know why.

Ranking 3 is also based on TTLB's data, but this ranking is based not on links but on hits.

Although a lot of data is missing for the TTLB-hits rankings, the agreement between the TTLB rankings for the 22 blogs that have values for both is quite reasonable (simple correlation coefficient = .819; Spearman's rho = .798). One interesting point raised by this table is that with three mild exceptions (Dresner, Worstall, and Prestopundit), the rankings of economics blogs based on hits are higher than their rankings based on links, sometimes substantially so.

I leave explaining this as an exercise for the reader.

Finally, ranking 4, using information from Google. Google currently claims to index over 8 billion Web pages. Google assigns each of those pages a PageRank, concisely characterized as "Google's measure of the importance of [the] page".

PageRanks are integers from 0 to 10, 10 being most important. I read a while back (but can't now find the source) that 10s are very rare, on the order of only two or three dozen. In a few of minutes of looking I found only four: Google itself, the New York Times, Harvard, and Statcounter. MIcrosoft, AOL, the Washington Post, Yahoo, Yale, and Oxford are among the sites that earn only a 9. Wal-Mart and General Motors are 8s. The very well-known blogs Instapundit, Daily Kos, and Drudge Report each earn a 7.  I have absolutely no evidence for this, but I guess PageRank might be logarithmic, like the Richter Scale.

The rest of the economics blogs I checked had a PageRank of 5 or lower.

The clear winner in this ranking is Brad DeLong. A PageRank of 8 is quite impressive. 8s are earned by such hugely popular and important sites as Fark, Boing Boing, and Metafilter, and as noted, an 8 is higher than earned by Instapundit and Drudge. DeLong's is also the one of only two economics blogs listed in the top 100 blogs at Technorati (currently #84 among "13.8 million blogs"; the other is Crooked Timber at #60. Thanks to Henry Farrell for the correction.)

(This despite the fact that Professor DeLong once left a comment here that commanded me, "Don't be an idiot". Good advice generally, but not in that instance.)

There are twelve economics blogs with a PageRank of 7, and twenty-six, including yours truly, with a PageRank of 6.

I looked at a few other possible sources for data--Blogstreet, Bloogz, Popdex, and Technorati--but for one reason or another, I found them generally unhelpful.

Here are some of the serious limitations of these rankings.

1. We first need to decide 1) what a blog is and 2) what an economics blog is. Is a blog an economics blog based on its author(s) or its content or both?  Threshold percentages must be defined: what should they be? There clearly are no single answers to these questions.

Purely for convenience, I started with the list of 93 sources that Professor William R. Parke consults for his very useful Economics Roundtable.

2. But I didn't want to take the time to check all 93. I ended up checking 47 of the 93 (more than I initially intended). But the 47 I checked were not randomly selected; those chosen reflect my knowledge and preferences. I looked at blogs I think are best; blogs I read; and some others I was curious about. For the same reasons, and with the same non-randomness, I investigated an additional 19 blogs. In this set of 66 blogs, non-U.S. bloggers and left-wing bloggers are probably underrepresented. (But some of the sources I omitted wouldn't qualify as an "economics blog" under any reasonable defintion. Slate, for example.)

3. What time period should be used for the ranking? Life of the blog? Five years? Three months? Again, there's no "right" answer. Blogpulse uses 30 days. I'm not clear what time period TTLB and Google use. (I have no definitive information, but it seems as though Google penalizes younger blogs somewhat.)

4. Rankings based on "hits" and "links" are both problematic. Some hits are from people using search engines poorly. Some hit recorders capture just hits to the main URL and don't capture hits to individual pages or to individual posts. Some links might be from people who looked at the blog five years ago, once, and haven't updated their links. Links may well favor older blogs, because people didn't have as much to look at in the early days of the Web.

5. Except for the Google ranking, a lot of data is missing in the sources for the other rankings. I don't know why.

6. Just like student rankings via SAT scores and rankings of colleges and universities via U. S. News & World Report, "small" differences in ranks are statistically unreliable and substantively unimportant. The problem is that I see no way of knowing what "small" is. (The Google PageRank ameliorates this problem.)

7. With some effort all of these rankings could be gamed. Google would be hardest, but there's an industry devoted to advising people how to inflate their PageRank. For all I know, some of the blogs in this little study may already made such an effort.

8. I did this very fast, with minimal double-checking of data entry.

A note: I compiled the rankings Friday night and Saturday (7/22 and 7/23). By the time you read this, there could well be changes to the source data.

I don't intend to spend much, if any, additional time on this. But I'd be happy to email an Excel spreadsheet with my data, including URLs for all the listed blogs, to anyone who asks.

UPDATE 1: The Emirates Economist ranks 40th in ranking number 2 and 21st in ranking number 3.

UPDATE 2: The Google PageRank of voluntaryXchange corrected from 5 to 6. Thanks, Dave!

UPDATE 3: SCSU Scholars places 13th in ranking #2 and 14th in ranking #3. It can be located in TTLB's data by omitting the space: SCSUScholars. Thanks, King!