Campus Life Fun With Numbers Life in Academia

Predictors of salary among faculty in the same department

At most public universities everyone’s salary is a matter of public record. It’s always fascinated me that we don’t talk about this more often. It means it is straightforward to look at the total variance in people’s salaries in the same role and test different ideas for what might explain the differences in compensation between different people in the same role. So let’s take a look!

In my own department there are ~45 faculty with research appointments and entries in our school’s 21-22 salary database: Eight assistant professors, fifteen associate professors, and twenty-one full professors. Since assistant professors want to get promoted to associate professor and associate professors want to get promoted to full professors, the simplest model I can think of is to look at how well professor rank predicts salary.

Faculty salaries by academic rank within a single department.
Faculty salaries by academic rank.

Okay, so our extremely naive model is clearly on to something: average salary increases as people get promoted. But also salaries are much more widely distributed amongst full professors than among assistant professors. Lots of things that could be driven by. But what about the classic “let’s boil down research productivity to a single metric”: the h-index? Only 36 of the 45 professors in my department have google scholar profiles. But that’s not the big problem.

Fun With Numbers

Yield of Arabidopsis

Arabidopsis thaliana.

Arabidopsis thaliana is a plant which though its small size, possession of the first sequenced plant genome (released in 2000 four years before the complete human genome), and short generation time* has become a common sight in plant biology labs around the world. From an applied standpoint, the main problem with Arabidopsis research is that, like any model organizism, sometimes biologists discover things that are broadly applicable to the plant world (including important crop species, from apricots to zuccinnis) and sometimes their discoveries turn out to be specific to arabidopsis and some of its close relatives.

Since Arabidopsis is probably now the most studied plant on the planet, could we cut out the middle-man and simply grow fields of arabidopsis? You’re about to become one of the few people who knows the answer to that question.

Fun With Numbers

The top ten instutitions attending the 52nd Maize Meeting this March

As determined by the domain names of 402 e-mail addresses that were recently revealed.

  1. Cornell University
  2. Google <– was the second most common domain name among these e-mail addresses.
  3. Cold Spring Harbor
  4. University of Guelph
  5. Iowa State University
  6. University of California-Berkeley
  7. University of Florida
  8. UMR de Génétique Végétale du Moulon*
  9. (8) Purdue University*
  10. Syngenta

Overall a total of 134 organizations (or at least domain names) were represented in the list of e-mail addresses of attendees in my possession. If I could dig up historical data it’d be interesting to see how the rankings change over time.

Doing this sort of analysis very quickly (generating the data for this post took ~4 minutes, I timed myself) is one of the fringe benefits of learning even a little about programming.

Official 52nd Maize Meeting website.

(You see what happens when a guy has too much caffeine and then has a chunk of time too short to get any real work done?!)

*These two institutions are tied for number of attendees

Fun With Numbers

Even Faster Sequencing

Just five years ago in 2005, the state of the art technology for sequencing genomes was Sanger sequencing, the same basic technology that had been used by biologists for decades, although the sequencers of 2005 were the result of decades of refinement of the basic technique. Five years later in 2010, the newest state of the art sequencer is the HiSeq 2000 from Illumina (at least until the Pacific Biosystems sequencers become available later this year… ::drool::). What difference does 5 years make? It would take more than thirty-thousand of the latest and greatest sanger sequencers from 2005 (right before the first next generation sequencer, a 454 machine built by Roche, was released) to produce as much DNA sequence data as a single one of the new HiSeq 2000s produces.*

Fun With Numbers Politics Uncategorized

Not 2 + 2 = 5, but close

Among the many things Michael Specter talks about in his new book Denialism, is that fact that numeracy (the mathmatical equivalent of literacy) is no longer prized in todays society.

Case in point:

BP, for example, puts $1.3 billion to $1.6 billion a year into alternative energy projects. That’s about 1 percent of the company’s total $20 billion investment this year in future business prospects.*

I was going to beat up on the greenpeace blog where I read this sentence, but on a closer rereading I realized it was actually a direct quote from this article on the New York Times website. Come on people, 1% is easy, all you do is move the decimal place, you don’t even have to divide or multiply. Now there could be some obscure accounting reason that regular math doesn’t apply here, but if so it should have been mentioned and it wasn’t.

agriculture Fun With Numbers Politics

By The Numbers 12/19/09

In no way should any of the following statistics be taken as a dig against the people who study wheat. Wheat breeders have done so much with far few resources than have been invested in maize (corn) breeding. Ya’ll are amazing.
  • Year in with the largest wheat harvest in the US: 1981-1982 (2.8 billion bushels)
  • Year in with the largest wheat corn harvest in the US: 2007-2008(13 billion bushels)
  • The US’s share of global wheat exports in 1973-1974: 50%
  • The US’s share of global wheat exports today: 20%
  • Percentage increase in yield per acre of wheat 1969-present: 45%
  • Percentage increase in yield per acre of corn 1969-present: 90%
  • Estimated earliest year a program to develop genetically engineered wheat, launched today, would be able to win regulatory approval for any variety of GM wheat: 2018
  • Year in which Monsanto’s patent on their first generation Round-up Ready Soybeans expires: 2014
  • Number of lawsuits filed by Monsanto against individual farmers it claims infringed on its seed patents in the past decade: 125 (same source as above)
  • Number people threatened with legal action to force a settlement/sued by the RIAA in the same time period: more than 28,000
  • Amount the RIAA sued the russian website for in 2006: $1.65 trillion
  • The gross domestic product of India in 2008: $1.2 trillion
  • First time the world knew what the far side of the moon looked like: 1959

Check out the article in The Guardian about wheat farming and the future of genetically engineered wheat.

agriculture Feeding the world Fun With Numbers Plant breeding

More on the Good Guys (CGIAR)

Tracked down a paper published just under a year ago in Food Policy (a peer reviewed journal). “The impact of agricultural research on productivity and poverty in sub-Saharan Africa” by Arega Alene and Ousmane Coulibaly.* 

CGIAR spending on research targeted at agriculture in Sub-Saharan Africa (178 million dollars a year in 2003) provides 1.3 million people with an escape from extreme poverty (living one dollar a day or less) every year. Simple division would indicate the agricultural research of the CGIAR centers is saving human beings from the trap of extreme poverty at a cost of just under 137 dollars per person. Of course it isn’t that simple, there are both economies of scale** and, eventually, diminishing margins of return*** to consider, but it seems the work of the CGIAR centers in Africa are big enough to have achieved those economies of scale, and, given their calculations on the elasticity on poverty to investment in agriculture, Africa is a LONG way from having to worry about diminishing marginal returns on agricultural investment.

Given the elasticity of poverty reduction to agricultural research spending they calculate (-.22) the marginal cost* of reducing poverty by another person in Sub-Saharan Africa through investments in agricultural research is only $71. (i.e. spending one billion dollars more on agricultural research would save an additional 14 million people from poverty.) This doesn’t consider the additional postive effects of improving local agriculture (for example reducing the incidence of famine).

Finally consider this quote from the paper for a sense of the work the CGIAR centers are funding and try not to feel as impressed as I do:

Fun With Numbers

Quick Question On Student Debt

Numbers in this post come from from The Project on Student Debt. I can’t vouch for their accuracy myself, but assuming they are:

Which of these numbers do you think is more informative?

  1. Among college students in Iowa graduating with debt, the average amount owed was $28,174 (73% of students graduated with debt)
  2. Among all college students who graduated in Iowa last year, the average student owed $20,567?
Feeding the world Fun With Numbers

Could we feed ourselves with tomatoes?

Obviously no one is suggesting turning the US into a tomato monoculture, but tomatoes seem like a easy, if not necessarily accurate, proxy for the sort of fresh vegetable passed diets that some people advocate as a solution for the entire nation. If the did the same calculation for lettuce, the numbers would likely be much worse. If I did it for sweet potatoes, I’m guessing they would be substantially better.

There is a very useful resource on growing tomatoes made available by the Iowa State extension service. They estimate yields of 12,000-16,000 pounds of tomato per acre. A pound of tomatoes contains 86 calories.

agriculture Feeding the world food Fun With Numbers

About the herbicide application report that’s floating around

I’m sure everyone who follows the genetic engineering debate has heard about the report from The Organic Center which lays a net increase in pesticide usage at the feet of genetically engineered crops. So I finally found a link to the report itself [warning pdf, also 69 pages]. I’m neither a statistician nor an agronomist (despite my awesome ISU hat which has exactly that slogan), so I’m not qualified to confirm or refute the numbers they put forward. Hopefully we’ll see more detailed analysis on that end from someplace like Biofortified or Sustainablog. I now have some analysis of the methodology of the report itself, tracked down by gntis on the biofortified forums. What I can do is given a bit of the broader context about the context of their numbers and what they don’t mean. This post will be in the following format:

  • The 318 million pounds in context
  • Chemicals are different
  • –Different Toxicity
  • –Different Persistance in the Environment
  • Herbicide resistant weeds
  • One trait vs a technology

318 Million Pounds in Context

Example tweet:

Pesticide use has skyrocketed by 318 million lbs (in last 13 years) with use of #GMO seeds!

Let’s put that number in perspective.