More Like this

1. Subgroup-effects models for the analysis of personal treatment effects

   https://doi.org/10.1214/21-AOAS1503  

   Zhou, Ling; Sun, Shiquan; Fu, Haoda; Song, Peter X.-K. (March 2022, The Annals of Applied Statistics)
2. Nonparametric estimation of marginal effects in regression-spline random effects models

   https://doi.org/10.1080/07474938.2020.1772569  

   Ma, Shujie; Racine, Jeffrey S.; Ullah, Aman (September 2020, Econometric Reviews)
3. Negative effects of nitrogen override positive effects of phosphorus on grassland legumes worldwide

   https://doi.org/10.1073/pnas.2023718118  

   Tognetti, Pedro M.; Prober, Suzanne M.; Báez, Selene; Chaneton, Enrique J.; Firn, Jennifer; Risch, Anita C.; Schuetz, Martin; Simonsen, Anna K.; Yahdjian, Laura; Borer, Elizabeth T.; et al (July 2021, Proceedings of the National Academy of Sciences)

   null (Ed.)

   Anthropogenic nutrient enrichment is driving global biodiversity decline and modifying ecosystem functions. Theory suggests that plant functional types that fix atmospheric nitrogen have a competitive advantage in nitrogen-poor soils, but lose this advantage with increasing nitrogen supply. By contrast, the addition of phosphorus, potassium, and other nutrients may benefit such species in low-nutrient environments by enhancing their nitrogen-fixing capacity. We present a global-scale experiment confirming these predictions for nitrogen-fixing legumes (Fabaceae) across 45 grasslands on six continents. Nitrogen addition reduced legume cover, richness, and biomass, particularly in nitrogen-poor soils, while cover of non–nitrogen-fixing plants increased. The addition of phosphorous, potassium, and other nutrients enhanced legume abundance, but did not mitigate the negative effects of nitrogen addition. Increasing nitrogen supply thus has the potential to decrease the diversity and abundance of grassland legumes worldwide regardless of the availability of other nutrients, with consequences for biodiversity, food webs, ecosystem resilience, and genetic improvement of protein-rich agricultural plant species. 

   more » « less
4. Attitudinal Effects of Stimulus Co-occurrence and Stimulus Relations: Paradoxical Effects of Cognitive Load

   https://doi.org/10.1177/01461672211044322  

   Gawronski, Bertram (January 2022, Personality and Social Psychology Bulletin)

   Research suggests that evaluations of an object can be jointly influenced by (a) the mere co-occurrence of the object with a pleasant or unpleasant stimulus (e.g., mere co-occurrence of object A and negative event B) and (b) the object’s specific relation to the co-occurring stimulus (e.g., object A starts vs. stops negative event B). Three experiments investigated the impact of cognitive load during learning on the effects of stimulus co-occurrence and stimulus relations. Counter to the shared prediction of competing theories suggesting that effects of stimulus relations should be reduced by cognitive load during learning, effects of stimulus relations were greater (rather than smaller) under high-load compared with low-load conditions. Effects of stimulus co-occurrence were not significantly affected by cognitive load. The results are discussed in terms of theories suggesting that cognitive load can influence behavioral outcomes via strategic shifts in resource allocation in response to task-specific affordances. 

   more » « less
5. Downstream Effects of Affirmative Action

   https://doi.org/10.1145/3287560.3287578  

   Kannan, Sampath; Roth, Aaron; Ziani, Juba (January 2019, ACM FAT* 2019)

   We study a two-stage model, in which students are 1) admitted to college on the basis of an entrance exam which is a noisy signal about their qualifications (type), and then 2) those students who were admitted to college can be hired by an employer as a function of their college grades, which are an independently drawn noisy signal of their type. Students are drawn from one of two populations, which might have different type distributions. We assume that the employer at the end of the pipeline is rational, in the sense that it computes a posterior distribution on student type conditional on all information that it has available (college admissions, grades, and group membership), and makes a decision based on posterior expectation. We then study what kinds of fairness goals can be achieved by the college by setting its admissions rule and grading policy. For example, the college might have the goal of guaranteeing equal opportunity across populations: that the probability of passing through the pipeline and being hired by the employer should be independent of group membership, conditioned on type. Alternately, the college might have the goal of incentivizing the employer to have a group blind hiring rule. We show that both goals can be achieved when the college does not report grades. On the other hand, we show that under reasonable conditions, these goals are impossible to achieve even in isolation when the college uses an (even minimally) informative grading policy 

   more » « less