The Ash Twins Blog

Economics articles published in peer-reviewed journals doubled in average length between 1970 and 2000.[1] The length of the publication process increased even faster, however, more than doubling.[2] The number of slots in top journals has increased, but they have also become more prestigious, so competition to publish in the top journals increased intensely during those decades.[3] Ellison believes that the lengthier publication process “reflect[s] a shift in arbitrary social norms for what journals are supposed to ask authors to do and what published papers should look like. The one piece of support I can provide for the arbitrary social norm view is that the length of the review process varies from field to field within economics.”[4]

[1] Glenn Ellison, “The slowdown of the economics publishing process,” 110 Journal of Political Economy 947 (2002).

[2] Id.

[3] Id.

[4] Id. at 989.

From the respective entries in Wikipedia:

In physics, jerk, also known as jolt (especially in British English), surge and lurch, is the rate of change of acceleration; that is, the derivative of acceleration with respect to time, the second derivative of velocity, or the third derivative of position. Jerk is defined by any of the following equivalent expressions:

where

is acceleration,

is velocity,

is position

http://en.wikipedia.org/wiki/Jerk_%28physics%29

t is time.

…

In physics, jounce or snap is the fourth derivative of the position vector with respect to time, with the first, second, and third derivatives being velocity, acceleration, and jerk, respectively; in other words, the jounce is the rate of change of the jerk with respect to time.

Currently, there are no well-accepted designations for the derivatives of jounce. The fifth and sixth derivatives of position as a function of time are “sometimes somewhat facetiously” referred to (in association with “Snap”) as “Crackle” and “Pop”, from the cereal characters; however, these terms have not gained widespread acceptance.

Economists have produced a fair amount of data on factors contributing to scholarly productivity in their discipline. For example, graduating from a top graduate program is associated with a 22 percent increase in research productivity.[1] For each additional manuscript that a PhD candidate has under review before taking his or her first job, average annual productivity increases by 10 percent.[2] For a given economist, and holding innate ability constant, obtaining an initial placement at a higher-ranked institution is associated with long-term increases in professional productivity.[3]

Studies have found several factors to be most important for increased productivity. For each paper presented at a conference, productivity increases by 16 percent for that year.[4] Economists at doctoral-granting departments publish 47 percent more than their colleagues at departments that offer only an undergraduate degree.[5] A summer stipend increases annual research productivity by 11 percent.[6] Each of these items presumably increases incentives or reduces constraints on publication.

Some other factors are known to reduce productivity. For each 3-hour class taught in a year, research productivity decreases by 9.6 percent.[7] Each assignment to an administrative committee decreases productivity by 7 percent, while serving as department chair or program director decreases productivity by 42 percent.[8] Participating in for-profit consulting decreases productivity by 9.76 percent.[9] As with any job, these alternative uses of time reduce productivity.

A more intrinsic correlate of productivity is the age of the researcher. Taylor et al. find that productivity decreases by 1.9 percent per year of experience.[10] Oster and Hamermesh find an even more dramatic aging effect, with an annual decrease in productivity of 5 percent.[11] Age does not affect the probability that an article submitted to a leading journal will be accepted, however.[12] A related finding is that Nobel laureates make their “most important and creative contributions” between the ages of 29 and 38, slightly lower than that found in physics laureates.[13]

Only 20 percent of economists have published a book, but 10 percent have published more than one book.[14] Ten percent of top-school economists have never published an article; 75 percent of lower-school economists have never published an article.[15] Forty percent of economists have published six or more articles.[16] Economists who have not published a refereed journal article in the first 7 years are unlikely ever to do so.[17]

The social aspects of academic productivity are exemplified by the importance of one’s dissertation advisor. According to data reported by Hilmer and Hilmer, “students working with prominent advisors are significantly more likely to publish in their early careers, especially in top 36 journals, than students working with less prominent advisors.”[18] This advisor effect, moreover, is more important than the effect of one’s PhD department. Students at lower-ranked programs working with “superstar faculty” have more publications, and in more prestigious journals, than students at higher-ranked programs working with less distinguished faculty.[19]

Another example of the importance of social ties in research productivity is the impact of co-authorship. Publishing economists have an average of 0.57 authors per paper, suggesting that the average economist coauthors some papers and works alone on others.[20] Taylor et al.’s data suggest that increasing the number of coauthors increases average annual research productivity by 22.5 percent for the participating co-authors, but with diminishing increases in productivity as the number of authors increases above two.[21] An older paper found that co-authored papers are of higher quality; for n authors, they are n times as influential.[22] Most “fundamental work” by Nobel laureates, however, has been written alone.[23] In economics, the tradition is to name the authors in alphabetical order. One of the side effects of this is that economists with names earlier in the alphabet receive durable career advantages in terms of productivity and promotions.[24]

[1] Blakely Fox Fender, Susan Washburn Taylor, & Kimberly Gladden Burke, “Making the big leagues: Factors contributing to publication in elite economics journals,” 33 Atlantic Economic Journal 93 (2005).

[2] Susan Washburn Taylor, Blakely Fox Fender& Kimberly Gladden Burke, “Unraveling the Academic Productivity of Economists: The Opportunity Costs of Teaching and Service,” 72 Southern Economics Journal 846 (2006).

[3] Paul Oyer, “Initial Labor market conditions and long-term outcomes for economists,” 20 Journal of Economic Perspectives 143 (2006).

[4] Taylor et al. 2006. 

[5] Id.

[6] Id.

[7] Id.

[8] Id.

[9] Blakely Fox Fender, Susan Washburn Taylor, & Kimberly Gladden Burke, “Making the big leagues: Factors contributing to publication in elite economics journals,” 33 Atlantic Economic Journal 93 (2005).

[10] Susan Washburn Taylor, Blakely Fox Fender& Kimberly Gladden Burke, “Unraveling the Academic Productivity of Economists: The Opportunity Costs of Teaching and Service,” 72 Southern Economics Journal 846 (2006).

[11] Sharon M. Oster and Daniel S. Hamermesh, “Aging and productivity among economists,” 80 Review of Economics and Statistics 154 (1998).

[12] Id.

[13] van Dalen 1999.

[14] James E. Hartley, James W. Monks, & Michael D. Robinson, “Economists’ publication patterns,” 45 American Economist 80 (2001).

[15] Id.

[16] Id.

[17] Id.

[18] Michael J. Hilmer & Christiana E. Hilmer, “Fishes, Ponds, and Productivity: Student-advisor matching and early career publishing success for economics PhDs,” 47 Economic Inquiry 290 (2009).

[19] Id.

[20] Susan Washburn Taylor, Blakely Fox Fender& Kimberly Gladden Burke, “Unraveling the Academic Productivity of Economists: The Opportunity Costs of Teaching and Service,” 72 Southern Economics Journal 846 (2006).

[21] Id.

[22] Raymond D. Sauer, “Estimates of the Returns to Quality and Coauthorship in Economic Academia,” 96 Journal of Political Economy 855 (1988).

[23] Hendrik P. van Dalen, “The Golden Age of Nobel Economists,” 43 American Economist (1999).

[24] Mirham van Praag & B.M.S. van Praag, “The Benefits of Being Economics Professor A (and not Z),” IZA Discussion Paper No. 2673 (March 2007).

Some interesting facts about the undergraduate origins of economics PhD students (Siegfried and Stock, 2007):

• The leading undergraduate incubator of American economic PhDs is Korea’s Seoul University, which sends more than twice as many as Harvard.
• Twenty-four out of the top 25 PhD-creating undergraduate schools are private; “the one public institution (College of William and Mary) is the closest thing there is to a liberal arts college in the public sector.”
• Eighteen of the top 25 are liberal arts colleges without graduate programs. Siegfried and Stock (2007) propose a few explanations for this trend: 1) 50% of professors’ children attend such schools, and they follow in their parents’ footsteps, 2) undergraduate economics students at these colleges receive more attention from faculty than would otherwise be dedicated to grad students at research universities, and 3) these schools require their undergraduates to write twice as many term papers, on average, than similar programs at larger universities.

The differences between lawyers and economists can often be distilled to one of ends rather than means: Lawyers are interested in determining the just ends of social policy; economists are interested in the most efficient means to a given social policy. George Stigler (an economist) writes that

The difference between a discipline that seeks to explain economic life (and, indeed, all rational behavior) and a discipline that seeks to achieve justice in regulating all aspects of human behavior is profound. This difference means that, basically, the economist and the lawyer live in different worlds and speak different languages.[1]

Earlier in his career, Stigler had elaborated on this argument:

No important group of economists any longer believes that economics can tell a society what its goals should be… The legal profession, on the contrary, knows what one great goal of economic policy should be: justice.[2]

Legal arguments from justice and fairness—being unfalsifiable in the sense discussed above—often lead to multiple inconsistent policy conclusions. Stigler asked that lawyers adopt a more empiricist mindset, hoping that an understanding of legal processes would assist legal policy, just as economic processes assist market policy. Stigler writes:

The law is a collection of social machinery, and one would have thought that its engineers would study the appropriate functions of the various machines. If litigation between contracting parties is expensive and uncertain in one set of transactions but economical and consistent in another, we need to know their respective characteristics. If an administrative body can deal efficiently with one class of problems but is incapable of handling another type, again we need to know their respective characteristics. Lawyers have answers to these questions, and wise and informed lawyers may have good answers, but the answers are not based upon analyses of a type accepted as persuasive in the social or natural sciences.[3]

Understanding the mechanisms of legal systems will facilitate improvements in social policy. Stigler’s prediction that lawyers would play a critical role in marrying law and economics has since been borne out.

Lawyers cannot play an effective role in this enterprise without training themselves to engage in rigorous empirical research, however. Even among law-and-economics scholars, the dearth of empirical research in law schools is painfully evident. In a sample of articles between 1972 and 2002, 72% of articles at Journal of Law and Economics—mainly for economics professors—were empirical, while only 39% of articles in Journal of Legal Studies—mainly for law professors—were empirical.[4] This disparity is partly explained by the fact that learning basic microeconomic theory is not costly and has a significant scholarly payoff, while empirical work requires years of costly formal training and is considered contemptible by peers on the law faculty.[5] Law professors willingly invest in the former but not in the latter.

[1] George Stigler, “Law or Economics?” 35 Journal of Law and Economics 455 (1992).

[2] George Stigler, “The law and economics of public policy: A plea to the scholars,” 1 Journal of Legal Studies 1 (1972).

[3] Id.

[4] William Landes, “The empirical side of law & economics,” 70 University of Chicago Law Review 167 (2003).

[5] Id. at 180 (“It would only be a modest exaggeration to say that most law professors regard empirical work as a form of drudgery not worthy of first-class minds.”); see also Landes 1997, at 16-17 (“This difference cannot be accounted for solely by differences in data availability. There are substantial bodies of data on the number and disposition of criminal and civil cases at both the trial and appellate levels, awards in civil cases, sentences in criminal cases, earnings of lawyers, accident rates and so forth. Moreover, computerized legal databases make it possible at relatively low cost to extract significant amounts of information from cases in order to develop data sets relevant to the problems at hand.”)

I wasn’t familiar with the following quick-and-dirty treatment for people suffering from depression:

Postpartum depression affects between 5 percent and 25 percent of new mothers.  Symptoms — including sadness, fatigue, appetite changes, crying, anxiety and irritability — usually occur in the first few months after child birth.  There is a simple way to alleviate postpartum depression in just a few hours: sleep deprivation.

If a depressed mother stays up all night, or even the last half of the night, it is likely that by morning the depression will lift.  Although this sounds too good to be true, it has been well documented in over 1,700 patients in more than 75 published papers during the last 40 years.[1]  Sleep deprivation used as a treatment for depression is efficacious and robust: it works quickly, is relatively easy to administer, inexpensive, relatively safe and it also alleviates other types of clinical depression….

Neuroscientists have been trying to solve this puzzle.  The first hint of what may be happening during sleep came from J. Christian Gillin, a former colleague of mine at the University of California at San Diego and the San Diego Veterans Affairs Medical Center. Using imaging, he found that a small area of the cerebral cortex in the front of the brain  — the anterior cingulate cortex — which was consistently overactive in depressed patients, quieted to normal levels of activity after the patients were deprived of sleep. And when the patients were allowed to sleep, the activity in this area returned to the elevated levels.

Helen Mayberg at Emory University has shown that electrical stimulation of the anterior cingulate cortex, which disrupts normal activity, also reduces depression.  Some patients reported feeling immediate relief and calm after the procedure….

As you fall asleep, neurons in the brain stem that project throughout the cortex and keep it activated stop firing. The reduced stimulation from the brain stem disconnects the cortex from sensory input and there is a major shift in the pattern of electrical activity in the cortex. During the early part of the night the cortex is in a state of slow-wave sleep punctuated by brief periods of rapid-eye movement sleep (REM), which become more frequent and longer lasting toward early morning. One major class of antidepressants, tricyclics, blocks REM sleep, which suggests that sleep deprivation may work against depression the same way. This is consistent with the tendency for depressed individuals to sleep longer than they do when they feel normal. Additional support for this hypothesis comes from genetic studies of families with short REM latency — the tendency to enter REM early in the sleep cycle. This condition disrupts slow wave sleep and extends REM sleep. The risk of depression is much greater if you come from a family with this genetic background.

 

The following lecture by Yale biology professor Stephen Stearns provides an exceptional introduction and discussion of the application of evolutionary principles to human social behavior:

Not for the faint of heart: