Load-Sharing Policies in Parallel Simulation of Agent-Based Demographic Models

Execution parallelism in agent-Based Simulation (ABS) allows to deal with complex/large-scale models. This raises the need for runtime environments able to fully exploit hardware parallelism, while jointly offering ABS-suited programming abstractions. In this paper, we target last-generation Parallel Discrete Event Simulation (PDES) platforms for multicore systems. We discuss a programming model to support both implicit (in-place access) and explicit (message passing) interactions across concurrent Logical Processes (LPs). We discuss different load-sharing policies combining event rate and implicit/explicit LPs’ interactions. We present a performance study conducted on a synthetic test case, representative of a class of agent-based models

Time-triggering versus event-triggering control over communication channels

Time-triggered and event-triggered control strategies for stabilization of an unstable plant over a rate-limited communication channel subject to unknown, bounded delay are studied and compared. Event triggering carries implicit information, revealing the state of the plant. However, the delay in the communication channel causes information loss, as it makes the state information out of date. There is a critical delay value, when the loss of information due to the communication delay perfectly compensates the implicit information carried by the triggering events. This occurs when the maximum delay equals the inverse of the entropy rate of the plant. In this context, extensions of our previous results for event triggering strategies are presented for vector systems and are compared with the data-rate theorem for time-triggered control, that is extended here to a setting with unknown delay.Comment: To appear in the 56th IEEE Conference on Decision and Control (CDC), Melbourne, Australia. arXiv admin note: text overlap with arXiv:1609.0959

Scaling Rule for Nonperturbative Radiation in a Class of Event Shapes

We discuss nonperturbative radiation for a recently introduced class of infrared safe event shape weights, which describe the narrow-jet limit. Starting from next-to-leading logarithmic (NLL) resummation, we derive an approximate scaling rule that relates the nonperturbative shape functions for these weights to the shape function for the thrust. We argue that the scaling reflects the boost invariance implicit in NLL resummation, and discuss its limitations. In the absence of data analysis for the new event shapes, we compare these predictions to the output of the event generator PYTHIA.Comment: 23 pages, 3 figures, uses JHEP3.cls (included); v2 - version to appear in JHE

Decomposable Choice Under Uncertainty

Savage motivated his Sure Thing Principle by arguing that, whenever an act would be preferred if an event obtains and preferred if that event did not obtain, then it should be preferred overall. The idea that it should be possible to decompose and recompose decision problems in this way has normative appeal. We show, however, that it does not require the full separability across events implicit in Savage's axiom. We formulate a weaker axiom that suffices for decomposability, and show that this implies an implicit additive representation. Our decomposability property makes local necessary conditions for optimality, globally sufficient. Thus, it is useful in computing optimal acts. It also enables Nash behavior in games of incomplete information to be decentralized to the agent-normal form. None of these results rely on probabilistic sophistication; indeed, our axiom is consistent with the Ellsberg paradox. If we assume probabilistic sophistication, however, then the axiom holds if and only if the agent's induced preferences over lotteries satisfy betweenness.Sure-thing principle, decomposability, uncertainty, computation, dynamic programming solvability, agent-normal form games, non-expected utility, betweenness

The Consequences of Implicit and Explicit Beliefs on Food Preferences

Memories can have consequences on people's eating behavior. In the current experiment, we examined the effect of belief versus recollection on food preferences and then investigated whether explicit belief (i.e., self- reported) or implicit belief (i.e., measured by an autobiographical implicit association test; aIAT) had a similar effect on food preferences. Participants (N = 163) were falsely told that they got sick after eating egg salad in their childhood and then received guided imagery to induce false beliefs/recollections concerning the food-aversive event. Half of the participants with false memories were debriefed and told that the event was false to reduce their belief in the event. Belief, not recollection regarding the food-aversive event, impacted participants' food preferences. Furthermore, we found that explicit, but not implicit, belief predicted participants' food preferences. The current results suggest that explicit judgments of belief in a memory may explain the consequences resulting from memories

The Future of Price Distortion in Federal Securities Fraud Litigation

In its recent Halliburton decision, the Supreme Court focused on the role of price distortion in meeting the requirements for class certification in private securities fraud litigation. Accepting the argument that the fraud-on-the-market theory requires fraudulent information to have an effect on stock price, the Court reasoned that defendants should therefore be allowed to introduce evidence of lack of price impact in an effort to defeat class certification. Specifically, the Court suggested that defendants might introduce event studies as direct evidence that could sever the link between the misrepresentation and stock price. This conclusion, however, misapprehends the event study methodology. Specifically, the emphasis on event studies is misguided because the event studies proffered by defendants do not conclusively establish that the fraud did not distort stock price. More broadly, the limitations of existing quantitative methods suggest that they should not be the exclusive way of analyzing price distortion for purposes of class certification. Instead, the importance of price distortion suggests the need for greater consideration of materiality because a finding of materiality is an implicit determination that the information has the capacity to affect stock price

Aging in Structural Changes of Amorphous Solids: A Study of First Passage Time and Persistence Time Distribution

The time distribution of relaxation events in an aging system is investigated via molecular dynamics simulations. The focus is on the distribution functions of the first passage time, $p_1(\Delta t)$, and the persistence time, $p(\tau)$. In contrast to previous reports, both $p_1$ and $p$ are found to evolve with time upon aging. The age dependence of the persistence time distribution is shown to be sensitive to the details of the algorithm used to extract it from particle trajectories. By updating the reference point in event detection algorithm and accounting for the event specific aging time, we uncover age dependence of $p(\tau)$, hidden to previous studies. Moreover, the apparent age-dependence of $p_1$ in continuous time random walk with an age independent $p(\tau)$ is shown to result from an implicit synchronization of all the random walkers at the starting time

The demand for debt finance by entrepreneurial firms.

We model the entrepreneurial firm's choice of debt finance, allowing for debt renegotiations in the event of financial distress. We differentiate two sources of debt finance, bank debt and trade credit, by the implicit equity stake that lenders hold in the borrowing firm. Lenders with a large implicit equity stake, such as suppliers, may adopt a more lenient liquidation policy for their debtors, but then set a higher price for their credit. Entrepreneurs, who have private information about their probability of financial distress, borrow exclusively from lenders with a small implicit equity stake, such as banks, only when the price advantage of bank debt outweighs the cost of a stricter enforcement of liquidation rights. Entrepreneurs who prefer the lenient liquidation policy adopted by suppliers contract only partial bank finance in order to avoid a potential default against the bank later on. We show that the fraction of debt that consists of bank loans depends upon the cash flow in the bad state, the value attributed to control rights and the initial wealth and risk aversion of the entrepreneur.Demand; Entrepreneurs;

FLOODING RISK AND HOUSING VALUES: AN ECONOMIC ASSESSMENT OF ENVIRONMENTAL HAZARD

Climate change, the ‘boom and bust’ cycles of rivers, and altered water resource management practice have caused significant changes in the spatial distribution of the risk of flooding. Hedonic pricing studies, predominantly for the US, have assessed the spatial incidence of risk and the associated implicit price of flooding risk. Using these implicit price estimates and their associated standard errors, we perform a meta-analysis and find that houses located in the 100-year floodplain have a –0.3 to –0.8% lower price. The actual occurrence of a flooding event or increased stringency in disclosure rules causes ex ante prices to differ from ex post prices, but these effects are small. The marginal willingness to pay for reduced risk exposure has increased over time, and it is slightly lower for areas with a higher per capita income. We show that obfuscating amenity effects and risk exposure associated with proximity to water causes systematic bias in the implicit price of flooding risk.Manufactured Housing; valuation, environmental risk, meta-analysis, hedonic pricing