scholarly journals Alternative hypotheses and the volume of trade: the gravity equation and the extent of specialization

2004 ◽  
Vol 37 (1) ◽  
pp. 199-218 ◽  
Author(s):  
Jon Haveman ◽  
David Hummels
Keyword(s):  
Gravity Equation ◽  
Alternative Hypotheses ◽  
Volume Of Trade

scholarly journals The Gravity Equation in International Trade

2009 ◽  
Author(s):  
Michele Fratianni
Keyword(s):  
International Trade ◽  
Bilateral Trade ◽  
Gravity Equation ◽  
Trade Flows ◽  
Empirical Success ◽  
Theoretical Support ◽  
Long Time ◽  
Bilateral Trade Flows ◽  
Alternative Hypotheses ◽  
State Of Affairs

This article aims to explain trade flows in terms of the gravity equation (GE). The reason for focusing on GE is twofold. The first is that GE, unlike other frameworks, has had great empirical success in explaining bilateral trade flows. For a long time, however, GE was a child without a father in the sense that it was thought to have no theoretical support. Since the late 1970s, this state of affairs has changed radically. Now, the gravity equation has strong theoretical support and can be derived from a variety of models of international trade. The second is that GE can be used to sort out alternative hypotheses of international trade.

The Relationship of Interrogative Suggestibility to Memory and Attention

2006 ◽  
Vol 20 (2) ◽  
pp. 79-93 ◽  
Author(s):  
R.C. Howard ◽  
A. Chaiwutikornwanich
Keyword(s):  
Individual Differences ◽  
Short Story ◽  
Oddball Paradigm ◽  
Memory Processes ◽  
Memory And Attention ◽  
Irrelevant Distractors ◽  
Alternative Hypotheses ◽  
Visual Oddball Paradigm ◽  
Interrogative Suggestibility ◽  
Task Irrelevant

This study combined an individual differences approach to interrogative suggestibility (IS) with ERP recordings to examine two alternative hypotheses regarding the source of individual differences in IS: (1) differences in attention to task-relevant vis-à-vis task-irrelevant stimuli, and (2) differences in one or more memory processes, indexed by ERP old/new effects. Sixty-five female participants underwent an ERP recording during the 50 min interval between immediate and delayed recall of a short story. ERPs elicited by pictures that either related to the story (“old”), or did not relate to the story (“new”), were recorded using a three-stimulus visual oddball paradigm. ERP old/new effects were examined at selected scalp regions of interest at three post-stimulus intervals: early (250-350 ms), middle (350-700 ms), and late (700-1100 ms). In addition, attention-related ERP components (N1, P2, N2, and P3) evoked by story-relevant pictures, story-irrelevant pictures, and irrelevant distractors were measured from midline electrodes. Late (700-1100 ms) frontal ERP old/new differences reflected individual differences in IS, while early (250-350 ms) and middle latency (350-700 ms) ERP old/new differences distinguished good from poor performers in memory and oddball tasks, respectively. Differences in IS were not reflected in ERP indices of attention. Results supported an account of IS as reflecting individual differences in postretrieval memory processes.

Reply to Skousen and Aiuvalasit: On the Primacy of Archaeological Data

2020 ◽  
Vol 86 (1) ◽  
pp. 203-205
Author(s):  
A.J. White ◽  
Samuel E. Munoz ◽  
Sissel Schroeder ◽  
Lora R. Stevens
Keyword(s):  
Archaeological Evidence ◽  
Archaeological Data ◽  
The Past ◽  
Horseshoe Lake ◽  
Alternative Hypotheses

Skousen and Aiuvalasit critique our article on the post-Mississippian occupation of the Horseshoe Lake watershed (White et al. 2020) along two lines: (1) that our findings are not supported due to a lack of archaeological evidence, and (2) that we do not consider alternative hypotheses in explaining the lake's fecal stanol record. We first respond to the matter of fecal stanol deposition in Horseshoe Lake and then address the larger issue, the primacy of archaeological data in interpreting the past.

scholarly journals The Sampling Distribution of Disease-Associated Alleles

Genetics ◽  
1997 ◽  
Vol 147 (4) ◽  
pp. 1855-1861 ◽  
Author(s):  
Montgomery Slatkin ◽  
Bruce Rannala
Keyword(s):  
Low Frequency ◽  
Null Model ◽  
Sampling Distribution ◽  
Death Process ◽  
Published Data ◽  
Data Sets ◽  
Likelihood Functions ◽  
Alternative Hypotheses ◽  
Size Standard ◽  
Birth Death

Abstract A theory is developed that provides the sampling distribution of low frequency alleles at a single locus under the assumption that each allele is the result of a unique mutation. The numbers of copies of each allele is assumed to follow a linear birth-death process with sampling. If the population is of constant size, standard results from theory of birth-death processes show that the distribution of numbers of copies of each allele is logarithmic and that the joint distribution of numbers of copies of k alleles found in a sample of size n follows the Ewens sampling distribution. If the population from which the sample was obtained was increasing in size, if there are different selective classes of alleles, or if there are differences in penetrance among alleles, the Ewens distribution no longer applies. Likelihood functions for a given set of observations are obtained under different alternative hypotheses. These results are applied to published data from the BRCA1 locus (associated with early onset breast cancer) and the factor VIII locus (associated with hemophilia A) in humans. In both cases, the sampling distribution of alleles allows rejection of the null hypothesis, but relatively small deviations from the null model can account for the data. In particular, roughly the same population growth rate appears consistent with both data sets.

scholarly journals Distributions associated with simultaneous multiple hypothesis testing

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Chang Yu ◽  
Daniel Zelterman
Keyword(s):  
Latent Variable ◽  
Power Analysis ◽  
Marginal Distribution ◽  
Multiple Hypothesis Testing ◽  
Family Wise Error Rate ◽  
Uniform Distributions ◽  
Multiple Hypothesis ◽  
The Family ◽  
Alternative Hypotheses ◽  
Cancer Studies

Abstract We develop the distribution for the number of hypotheses found to be statistically significant using the rule from Simes (Biometrika 73: 751–754, 1986) for controlling the family-wise error rate (FWER). We find the distribution of the number of statistically significant p-values under the null hypothesis and show this follows a normal distribution under the alternative. We propose a parametric distribution ΨI(·) to model the marginal distribution of p-values sampled from a mixture of null uniform and non-uniform distributions under different alternative hypotheses. The ΨI distribution is useful when there are many different alternative hypotheses and these are not individually well understood. We fit ΨI to data from three cancer studies and use it to illustrate the distribution of the number of notable hypotheses observed in these examples. We model dependence in sampled p-values using a latent variable. These methods can be combined to illustrate a power analysis in planning a larger study on the basis of a smaller pilot experiment.

scholarly journals Family quarrels in seeds and rapid adaptive evolution in Arabidopsis

2019 ◽  
Vol 116 (19) ◽  
pp. 9463-9468 ◽  
Author(s):  
Katherine S. Geist ◽  
Joan E. Strassmann ◽  
David C. Queller
Keyword(s):  
Adaptive Evolution ◽  
Kin Selection ◽  
Conflicts Of Interest ◽  
A Priori ◽  
Flowering Plant ◽  
Rapid Adaptation ◽  
Arms Races ◽  
Evolutionary Conflict ◽  
Alternative Hypotheses

Evolutionary conflict can drive rapid adaptive evolution, sometimes called an arms race, because each party needs to respond continually to the adaptations of the other. Evidence for such arms races can sometimes be seen in morphology, in behavior, or in the genes underlying sexual interactions of host−pathogen interactions, but is rarely predicted a priori. Kin selection theory predicts that conflicts of interest should usually be reduced but not eliminated among genetic relatives, but there is little evidence as to whether conflict within families can drive rapid adaptation. Here we test multiple predictions about how conflict over the amount of resources an offspring receives from its parent would drive rapid molecular evolution in seed tissues of the flowering plant Arabidopsis. As predicted, there is more adaptive evolution in genes expressed in Arabidopsis seeds than in other specialized organs, more in endosperms and maternal tissues than in embryos, and more in the specific subtissues involved in nutrient transfer. In the absence of credible alternative hypotheses, these results suggest that kin selection and conflict are important in plants, that the conflict includes not just the mother and offspring but also the triploid endosperm, and that, despite the conflict-reducing role of kinship, family members can engage in slow but steady tortoise-like arms races.

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