A Critique of the CAP Theorem

The CAP Theorem is a frequently cited impossibility result in distributed systems, especially among NoSQL distributed databases. In this paper we survey some of the confusion about the meaning of CAP, including inconsistencies and ambiguities in its definitions, and we highlight some problems in its formalization. CAP is often interpreted as proof that eventually consistent databases have better availability properties than strongly consistent databases; although there is some truth in this, we show that more careful reasoning is required. These problems cast doubt on the utility of CAP as a tool for reasoning about trade-offs in practical systems. As alternative to CAP, we propose a "delay-sensitivity" framework, which analyzes the sensitivity of operation latency to network delay, and which may help practitioners reason about the trade-offs between consistency guarantees and tolerance of network faults

When A Factor Is Measured with Error: The Role of Conditional Heteroskedasticity in Identifying and Estimating Linear Factor Models

A new method is proposed for estimating linear triangular models, where identification results from the structural errors following a bivariate and diagonal GARCH(1,1) process. The associated estimator is a GMM estimator shown to have the usual √T-asymptotics. A Monte Carlo study of the estimator is provided as is an empirical application of estimating market betas from the CAPM. These market beta estimates are found to be statistically distinct from their OLS counterparts and to display expanded cross-sectional variation, the latter feature offering promise for their ability to provide improved pricing of cross-sectional expected returns.Measurement error; triangular models; factor models; heteroskedasticity; identification; many moments; GMM

Limiting Limited Liability

Limited liability may result in inefficient accident prevention, because a relevant portion of the expected harm is externalized on victims. This paper shows that under some restrictive conditions further limiting liability by means of a liability cap can improve caretaking.

Repurchase of renewal rights: a policy option for the National Water Initiative

Management of the Murray–Darling river system involves a large number of users with imprecisely defined rights, and an aggregate rate of resource use that is environmentally unsustainable. One possible policy response is to make formal or informal contracts with users, under which users receive current benefits in return for a commitment to forgo usage rights in future. In this paper, this issue is explored with specific reference to the possibility of repurchasing the renewal rights for irrigation licenses.National Water Initiative, Resource /Energy Economics and Policy,

When Spandrels Become Arches: Neural crosstalk and the evolution of consciousness

Once cognition is recognized as having a 'dual' information source, the information theory chain rule implies that isolating coresident information sources from crosstalk requires more metabolic free energy than permitting correlation. This provides conditions for an evolutionary exaptation leading to the rapid, shifting global neural broadcasts of consciousness. The argument is quite analogous to the well-studied exaptation of noise to trigger stochastic resonance amplification in neurons and neuronal subsystems. Astrobiological implications are obvious

Delegated causality of complex systems

A notion of delegated causality is introduced here. This subtle kind of causality is dual to interventional causality. Delegated causality elucidates the causal role of dynamical systems at the “edge of chaos”, explicates evident cases of downward causation, and relates emergent phenomena to Gödel’s incompleteness theorem. Apparently rich implications are noticed in biology and Chinese philosophy. The perspective of delegated causality supports cognitive interpretations of self-organization and evolution