Discover the most talked about and latest scientific content & concepts.

Concept: Productivity


To encourage worker productivity, companies routinely adopt policies requiring employees to delay gratification. For example, offices might prohibit use of the internet for personal purposes during regular business hours. Recent work in social psychology, however, suggests that using willpower to delay gratification can negatively impact performance. We report data from an experiment where subjects in a Willpower Treatment are asked to resist the temptation to join others in watching a humorous video for 10 minutes. In relation to a baseline treatment that does not require willpower, we show that resisting this temptation detrimentally impacts economic productivity on a subsequent task.

Concepts: Psychology, Sociology, Economics, Internet, Business, History of the Internet, Productivity, RESIST


Do highly productive researchers have significantly higher probability to produce top cited papers? Or do high productive researchers mainly produce a sea of irrelevant papers-in other words do we find a diminishing marginal result from productivity? The answer on these questions is important, as it may help to answer the question of whether the increased competition and increased use of indicators for research evaluation and accountability focus has perverse effects or not. We use a Swedish author disambiguated dataset consisting of 48.000 researchers and their WoS-publications during the period of 2008-2011 with citations until 2014 to investigate the relation between productivity and production of highly cited papers. As the analysis shows, quantity does make a difference.

Concepts: Evaluation, Sentence, Question, Answer, Productivity, Diminishing returns, Questions


The association between species richness and ecosystem energy availability is one of the major geographic trends in biodiversity. It is often explained in terms of energetic constraints, such that coexistence among competing species is limited in low productivity environments. However, it has proven challenging to reject alternative views, including the null hypothesis that species richness has simply had more time to accumulate in productive regions, and thus the role of energetic constraints in limiting coexistence remains largely unknown. We use the phylogenetic relationships and geographic ranges of sister species (pairs of lineages who are each other’s closest extant relatives) to examine the association between energy availability and coexistence across an entire vertebrate class (Aves). We show that the incidence of coexistence among sister species increases with overall species richness and is elevated in more productive ecosystems, even when accounting for differences in the evolutionary time available for coexistence to occur. Our results indicate that energy availability promotes species coexistence in closely related lineages, providing a key step toward a more mechanistic understanding of the productivity-richness relationship underlying global gradients in biodiversity.

Concepts: Biodiversity, Evolution, Species, Natural environment, Phylogenetic tree, Phylogenetics, Vertebrate, Productivity


The sensitivity of agricultural productivity to climate has not been sufficiently quantified. The total factor productivity (TFP) of the US agricultural economy has grown continuously for over half a century, with most of the growth typically attributed to technical change. Many studies have examined the effects of local climate on partial productivity measures such as crop yields and economic returns, but these measures cannot account for national-level impacts. Quantifying the relationships between TFP and climate is critical to understanding whether current US agricultural productivity growth will continue into the future. We analyze correlations between regional climate variations and national TFP changes, identify key climate indices, and build a multivariate regression model predicting the growth of agricultural TFP based on a physical understanding of its historical relationship with climate. We show that temperature and precipitation in distinct agricultural regions and seasons explain ∼70% of variations in TFP growth during 1981-2010. To date, the aggregate effects of these regional climate trends on TFP have been outweighed by improvements in technology. Should these relationships continue, however, the projected climate changes could cause TFP to drop by an average 2.84 to 4.34% per year under medium to high emissions scenarios. As a result, TFP could fall to pre-1980 levels by 2050 even when accounting for present rates of innovation. Our analysis provides an empirical foundation for integrated assessment by linking regional climate effects to national economic outcomes, offering a more objective resource for policy making.

Concepts: Regression analysis, Agriculture, Future, Economics, Economic growth, Productivity, Economics of production, Total factor productivity


Fish stocks fluctuate both in abundance and productivity (net population increase), and there are many examples demonstrating that productivity increased or decreased due to changes in abundance caused by fishing and, alternatively, where productivity shifted between low and high regimes, entirely unrelated to abundance. Although shifts in productivity regimes have been described, their frequency and intensity have not previously been assessed. We use a database of trends in harvest and abundance of 230 fish stocks to evaluate the proportion of fish stocks in which productivity is primarily related to abundance vs. those that appear to manifest regimes of high or low productivity. We evaluated the statistical support for four hypotheses: (i) the abundance hypothesis, where production is always related to population abundance; (ii) the regimes hypothesis, where production shifts irregularly between regimes that are unrelated to abundance; (iii) the mixed hypothesis, where even though production is related to population abundance, there are irregular changes in this relationship; and (iv) the random hypothesis, where production is random from year to year. We found that the abundance hypothesis best explains 18.3% of stocks, the regimes hypothesis 38.6%, the mixed hypothesis 30.5%, and the random hypothesis 12.6%. Fisheries management agencies need to recognize that irregular changes in productivity are common and that harvest regulation and management targets may need to be adjusted whenever productivity changes.

Concepts: Scientific method, Fish, Hypothesis, Theory, Regime, Overfishing, Productivity, Fishery



IMPORTANCE Describing the economic impact of childhood food allergy in the United States is important to guide public health policies. OBJECTIVE To determine the economic impact of childhood food allergy in the United States and caregivers' willingness to pay for food allergy treatment. DESIGN, SETTING, AND PARTICIPANTS A cross-sectional survey was conducted from November 28, 2011, through January 26, 2012. A representative sample of 1643 US caregivers of a child with a current food allergy were recruited for participation. MAIN OUTCOMES AND MEASURES Caregivers of children with food allergies were asked to quantify the direct medical, out-of-pocket, lost labor productivity, and related opportunity costs. As an alternative valuation approach, caregivers were asked their willingness to pay for an effective food allergy treatment. RESULTS The overall economic cost of food allergy was estimated at $24.8 (95% CI, $20.6-$29.4) billion annually ($4184 per year per child). Direct medical costs were $4.3 (95% CI, $2.8-$6.3) billion annually, including clinician visits, emergency department visits, and hospitalizations. Costs borne by the family totaled $20.5 billion annually, including lost labor productivity, out-of-pocket, and opportunity costs. Lost labor productivity costs totaled $0.77 (95% CI, $0.53-$1.0) billion annually, accounting for caregiver time off work for medical visits. Out-of-pocket costs were $5.5 (95% CI, $4.7-$6.4) billion annually, with 31% stemming from the cost of special foods. Opportunity costs totaled $14.2 (95% CI, $10.5-$18.4) billion annually, relating to a caregiver needing to leave or change jobs. Caregivers reported a willingness to pay of $20.8 billion annually ($3504 per year per child) for food allergy treatment. CONCLUSIONS AND RELEVANCE Childhood food allergy results in significant direct medical costs for the US health care system and even larger costs for families with a food-allergic child.

Concepts: Asthma, Costs, Allergy, Economics, Food allergy, Productivity, Opportunity cost, Economic cost


This study evaluated the effects of sit-stand desks on workers' objectively and subjectively assessed sitting, physical activity, and productivity. This quasi-experimental study involved one intervention group (n = 16) and one comparison group (n = 15). Participants were call center employees from two job-matched teams at a large telecommunications company in Sydney, Australia (45% female, 33 ± 11 years old). Intervention participants received a sit-stand desk, brief training, and daily e-mail reminders to stand up more frequently for the first 2 weeks post-installation. Control participants carried out their usual work duties at seated desks. Primary outcomes were workday sitting and physical activity assessed using ActivPAL or ActiGraph devices and self-report questionnaires. Productivity outcomes were company-specific objective metrics (e.g., hold time, talking time, absenteeism) and subjective measures. Measurements were taken at baseline, 1, 4, and 19 weeks post-installation. Intervention participants increased standing time after 1 week (+ 73 min/workday (95% CI: 22, 123)) and 4 weeks (+ 96 min/workday (95% CI: 41, 150)) post-intervention, while control group showed no changes. Between-group differences in standing time at one and 4 weeks were + 78 (95% CI: 9, 147) and + 95 min/workday (95% CI: 15, 174), respectively. Sitting time in the intervention group changed by - 64 (95% CI: - 125, - 2), - 76 (95% CI: - 142, - 11), and - 100 min/workday (95% CI: - 172, - 29) at 1, 4, and 19 weeks post-installation, respectively, while the control group showed no changes. No changes were observed in productivity outcomes from baseline to follow-up in either group. Sit-stand desks can increase standing time at work in call center workers without reducing productivity.

Concepts: Controlling for a variable, Scientific control, Change, Productivity, Subjectivity, American record labels, Desk


Scientists often perceive a trade-off between quantity and quality in scientific publishing: finite amounts of time and effort can be spent to produce few high-quality papers or subdivided to produce many papers of lower quality. Despite this perception, previous studies have indicated the opposite relationship, in which productivity (publishing more papers) is associated with increased paper quality (usually measured by citation accumulation). We examine this question in a novel way, comparing members of the National Academy of Sciences with themselves across years, and using a much larger dataset than previously analyzed. We find that a member’s most highly cited paper in a given year has more citations in more productive years than in in less productive years. Their lowest cited paper each year, on the other hand, has fewer citations in more productive years. To disentangle the effect of the underlying distributions of citations and productivities, we repeat the analysis for hypothetical publication records generated by scrambling each author’s citation counts among their publications. Surprisingly, these artificial histories re-create the above trends almost exactly. Put another way, the observed positive relationship between quantity and quality can be interpreted as a consequence of randomly drawing citation counts for each publication: more productive years yield higher-cited papers because they have more chances to draw a large value. This suggests that citation counts, and the rewards that have come to be associated with them, may be more stochastic than previously appreciated.

Concepts: Scientific method, Academic publishing, Science, Publishing, Productivity, Citation, Scientific literature, Publication


References are an essential component of research articles and therefore of scientific communication. In this study we investigate referencing (citing) behavior in five diverse fields (astronomy, mathematics, robotics, ecology and economics) based on 213,756 core journal articles. At the macro level we find: (a) a steady increase in the number of references per article over the period studied (50 years), which in some fields is due to a higher rate of usage, while in others reflects longer articles and (b) an increase in all fields in the fraction of older, foundational references since the 1980s, with no obvious change in citing patterns associated with the introduction of the Internet. At the meso level we explore current (2006-2010) referencing behavior of different categories of authors (21,562 total) within each field, based on their academic age, productivity and collaborative practices. Contrary to some previous findings and expectations we find that senior researchers use references at the same rate as their junior colleagues, with similar rates of re-citation (use of same references in multiple papers). High Modified Price Index (MPI, which measures the speed of the research front more accurately than the traditional Price Index) of senior authors indicates that their research has the similar cutting-edge aspect as that of their younger colleagues. In all fields both the productive researchers and especially those who collaborate more use a significantly lower fraction of foundational references and have much higher MPI and lower re-citation rates, i.e., they are the ones pushing the research front regardless of researcher age. This paper introduces improved bibliometric methods to measure the speed of the research front, disambiguate lead authors in co-authored papers and decouple measures of productivity and collaboration.

Concepts: Scientific method, Research, Rates, Introduction, Collaboration, Productivity, Inflation, Citation