Towards a Theory of Adaptation: X-Efficiency and Adaptive Efficiency

2020 ◽  
Author(s):  
Janice Alane Hauge ◽  
Laura Jamison ◽  
Mark A. Jamison
Keyword(s):  
Adaptive Efficiency

Adaptive efficiency of the Mexican Stock Exchange

2018 ◽  
Vol 31 (2) ◽  
pp. 326-335
Author(s):  
Esmeralda Brito-Cervantes ◽  
Semei Coronado ◽  
Manuel Morales-García ◽  
Omar Rojas
Keyword(s):  
Market Efficiency ◽  
Granger Causality ◽  
Latin American ◽  
Stock Exchange ◽  
Information Process ◽  
Causality Test ◽  
Content Type ◽  
Regulatory Policies ◽  
Adaptive Efficiency ◽  
Non Linear

Purpose The purpose of this paper is to analyse the adaptive market efficiency in the price–volume (P–V) relationship of the stocks listed in the Mexican Stock Exchange. The period under study goes from 1982 to 2015. In order to detect causality and, thus, determine adaptive efficiency in the market, one linear and two non-linear tests are applied. There are few papers in the literature that study the P–V relationship in Latin American markets; as such, this paper may be of interest and importance to financial academics and practitioners alike. Design/methodology/approach The Diks and Panchenko (DP) non-parametric Granger causality and the Brooks and Hinich (BH) cross-bicorrelation tests are applied. Findings Derived from the DP test, the findings show that there exists bi-directional non-linear Granger causality in 25.71 per cent of the firms studied, compared to 8 per cent when applying the linear Granger causality test. Therefore, there is evidence of weak-form efficiency in the market. From the BH test, evidence is shown of the adaptive market efficiency, since 71.42 per cent of firms exhibited some form of non-linear dependence in certain periods of time. With these results, the information process should be better studied for a greater comprehension of regulatory policies in the market and better decision-making tools for the investors. Originality/value This paper complements studies on the P–V relationship and efficiency in a Latin American market.

Covid-19 Mutations and How the Vaccine Enhances Immune Intelligence

2021 ◽  
Author(s):  
Xanya Sofra
Keyword(s):  
Amino Acid ◽  
Viral Entry ◽  
Open Reading Frames ◽  
Spike Protein ◽  
Single Amino Acid ◽  
Immune Memory ◽  
Type I ◽  
Specific Amino Acid ◽  
Adaptive Efficiency ◽  
Acid Exchange

We traced the coronavirus classification and evolution, analyzed the Covid-19 composition and its distinguishing characteristics when compared to SARS-CoV and MERS-CoV. Despite their close kinship, SARS-CoV and Covid-19 display significant structural differences, including 380 amino acid substitutions, and variable homology between certain open reading frames that are bound to diversify the pathogenesis and virulence of the two viral compounds. A single amino acid substitution such as replacing Aspartate (D) with Glycine (G) composes the D614G mutation that is around 20% more infectious than its predecessor 614D. The B117 variant, that exhibits a 70% transmissibility rate, harbours 23 mutants, each reflecting one amino acid exchange. We examined several globally spreading mutations, 501.V2, B1351, P1, and others, with respect to the specific amino acid conversions involved. Unlike previous versions of coronavirus, where random mutations eventually precipitate extinction, the multiplicity of over 300,000 mutations appears to have rendered Covid-19 more contagious, facilitating its ability to evade detection, thus challenging the effectiveness of a large variety of emerging vaccines. Vaccination enhances immune memory and intelligence to combat or obstruct viral entry by generating antibodies that will prohibit the cellular binding and fusion with the Spike protein, ultimately debilitating the virus from releasing its contents into the cell. Developing antibodies during the innate response, appears to be the most compelling solution in light of the hypothesis that Covid-19 inhibits the production of Interferon type I, compromising adaptive efficiency to recognize the virus, possibly provoking a cytokine storm that injures vital organs. With respect to that perspective, the safety and effectiveness of different vaccines is evaluated and compared, including the Spike protein mRNA version, the Adenovirus DNA, Spike protein subunits, the deactivated virus genres, or, finally, the live attenuated coronavirus that appears to demonstrate the greatest effectiveness, yet, encompass a relatively higher risk.

Robust Institutional Design

2016 ◽  
Author(s):  
Jenna Bednar
Keyword(s):  
System Design ◽  
Institutional Design ◽  
Structural Features ◽  
Institutional Adaptation ◽  
Adaptive Efficiency ◽  
Research Questions ◽  
Robust System ◽  
Institutional System ◽  
Robust Adaptive ◽  
Over Time

Institutions are designed to alter human behavior. To remain effective over time, institutions need to adapt to changes in the environment or the society the institution is meant to regulate. Douglas North referred to this property as adaptive efficiency and suggested the need for a model of how institutions change to remain effective. This essay contributes to a theory of adaptive efficiency by relating it to the burgeoning literature in robust system design. It reviews five models of institutional change, paying particular attention to each model’s ability to explain institutional adaptation. It isolates three common structural features of a robust, adaptive institutional system: diversity, modularity, and redundancy. It illustrates the theory with a brief application to federal systems, and closes by describing some open research questions relating to institutional adaptive efficiency.

Evaluating spatial transformation procedures as universals

2001 ◽  
Vol 24 (4) ◽  
pp. 697-698
Author(s):  
Lawrence M. Parsons
Keyword(s):  
Human Mind ◽  
Spatial Transformation ◽  
Spatial Transformations ◽  
Psychological Conditions ◽  
Adaptive Efficiency

Shepard proposes that the human mind relies on screw displacement because of its adaptive simplicity and uniqueness. I discuss this hypothesis by assessing screw displacement with respect to (1) other plausible spatial transformations, (2) a variety of criteria for adaptive efficiency and utility, and (3) a variety of psychological conditions in which observed responses discriminate amongst alternative spatial procedures. [Shepard]

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