A rush of blood to the head: Temporal dimensions of retrenchment, environment and turnaround performance

In this work we test the general assumption in the turnaround literature that time is critical for firm survival, especially during the retrenchment stage.We study three time dimensions of change at this stage: timing, speed and rhythm. Drawing on the downward spiral and threat-rigidity perspectives, we posit that the positive impact these time dimensions have on turnaround performance is highly contingent on two types of environment. Our findings, based on a sample of 263 declining US firms over a 26-year period (1983e2009), demonstrate that an early timing of retrenchment has a positive impact on performance when the environment is munificent. On the contrary, an early timing has a negative impact when the environment is dynamic. We also note that a fast pace of retrenchment positively impacts firm performance in dynamic environments. Finally, we find that declining firms display better performances when following an irregular rhythm of retrenchment, both in highly munificent and highly dynamic environments. Our results indicate that, in general, declining firm performance improves with time-aggressive retrenchment actions in both types of environment. We discuss the contribution of our research to the turnaround literature, and the downward spiral and threat-rigidity perspective

A diminishing population whose every cohort more than replaces itself

We observe that a dynamic population model can have period fertility that is always below replacement and cohort fertility that is always above replacement. We ask whether such a paradoxical population will get larger or smaller, and show that it must become smaller. Cohort replacement does not imply population replacement, and emphasizing fertility timing and cohort fertility ignores the issue of relative cohort size. The resolution of this apparent paradox reinforces the importance of the level of period fertility in demographic analysis.Bongaarts-Feeney adjusted fertility, cohort, cohort fertility, dynamic population model, fertility, fertility timing, period fertility

CIDPro: Custom Instructions for Dynamic Program Diversification

Timing side-channel attacks pose a major threat to embedded systems due to their ease of accessibility. We propose CIDPro, a framework that relies on dynamic program diversification to mitigate timing side-channel leakage. The proposed framework integrates the widely used LLVM compiler infrastructure and the increasingly popular RISC-V FPGA soft-processor. The compiler automatically generates custom instructions in the security critical segments of the program, and the instructions execute on the RISC-V custom co-processor to produce diversified timing characteristics on each execution instance. CIDPro has been implemented on the Zynq7000 XC7Z020 FPGA device to study the performance overhead and security tradeoffs. Experimental results show that our solution can achieve 80% and 86% timing side-channel capacity reduction for two benchmarks with an acceptable performance overhead compared to existing solutions. In addition, the proposed method incurs only a negligible hardware area overhead of 1% slices of the entire RISC-V system

Revisiting Mutual Fund Performance Evaluation

Mutual fund manager excess performance should be measured relative to their self-reported benchmark rather than the return of a passive portfolio with the same risk characteristics. Ignoring the self-reported benchmark introduces biases in the measurement of stock selection and timing components of excess performance. We revisit baseline empirical evidence in mutual fund performance evaluation utilizing stock selection and timing measures that address these biases. We introduce a new factor exposure based approach for measuring the – static and dynamic – timing capabilities of mutual fund managers. We overall conclude that current studies are likely to be overstating lack of skill because they ignore the managers’ self-reported benchmark in the performance evaluation process.Mutual funds, short-term performance, market timing, factor timing

Dynamic Choice and Timing-Independence: an experimental investigation

Timing-independence implies that individuals are indifferent between a sequential choice problem and a planned choice problem which are strategically equivalent except for the timing of resolution of the uncertainty. This paper reports an experiment in which we investigate whether the timing of resolution of the uncertainty affects individual preferences. We elicit individual preferences for three strategically equivalent decisions problems. The experimental results suggest that timing- independence is an inappropriate assumption of individual preferences. The paper discusses possible implications of such findings.

Collective modes of coupled phase oscillators with delayed coupling

We study the effects of delayed coupling on timing and pattern formation in spatially extended systems of dynamic oscillators. Starting from a discrete lattice of coupled oscillators, we derive a generic continuum theory for collective modes of long wavelength. We use this approach to study spatial phase profiles of cellular oscillators in the segmentation clock, a dynamic patterning system of vertebrate embryos. Collective wave patterns result from the interplay of coupling delays and moving boundary conditions. We show that the phase profiles of collective modes depend on coupling delays.Comment: 5 pages, 2 figure