Effects of Channelization on Fish Populations of the Cache River and Bayou DeView

This study was designed to better understand the possible effects of channelization by comparing natural and previously channelized sections of the Cache River and Bayou DeView. Forty-five fish species were collected in natural reaches, but only 24 species were collected in channelized reaches. Cyprinus carpio and Dorosoma cepedianum constituted 40 and 20 percent of the total fish biomass in channelized reaches, respectively, but only 22 and 2 percent of the total biomass in natural reaches. The mean weight of total fishes and game fishes only per surface ha in natural sections were 276 and 46 kg, respectively, but these values in channelized sections were only 88 and 2 kg, respectively. Mean species diversity indices for natural and channelized sections of the Cache River were 3.1 and 1.8, respectively, and mean redundancy values for these sections were .30 and .55, respectively. Species diversity indices and redundancy values for Bayou DeView followed this trend

Coordination Failure in Repeated Games with Almost-Public Monitoring

Some private-monitoring games, that is, games with no public histories, can have histories that are almost public. These games are the natural result of perturbing public-monitoring games towards private monitoring. We explore the extent to which it is possible to coordinate continuation play in such games. It is always possible to coordinate continuation play by requiring behavior to have bounded recall (i.e., there is a bound L such that in any period, the last L signals are sufficient to determine behavior). We show that, in games with general almost-public private monitoring, this is essentially the only behavior that can coordinate continuation play.Repeated games, Private monitoring, Almost-public monitoring, Coordination, Bounded recall

Coordination failure in repeated games with almost-public monitoring

Some private-monitoring games, that is, games with no public histories, can have histories that are almost public. These games are the natural result of perturbing public monitoring games towards private monitoring. We explore the extent to which it is possible to coordinate continuation play in such games. It is always possible to coordinate continuation play by requiring behavior to have bounded recall (i.e., there is a bound L such that in any period, the last L signals are sufficient to determine behavior). We show that, in games with general almost-public private monitoring, this is essentially the only behavior that can coordinate continuation play.Repeated games, private monitoring, almost-public monitoring, coordination, bounded recall

Coordination Failure in Repeated Games with Almost-Public Monitoring

Some private-monitoring games, that is, games with no public histories, can have histories that are almost public. These games are the natural result of perturbing public-monitoring games towards private monitoring. We explore the extent to which it is possible to coordinate continuation play in such games. It is always possible to coordinate continuation play by requiring behavior to have bounded recall (i.e., there is a bound L such that in any period, the last L signals are sufficient to determine behavior). We show that, in games with general almost-public private monitoring, this is essentially the only behavior that can coordinate continuation play.repeated games, private monitoring, almost-public monitoring, coordination, bounded recall

Coordination Failure in Repeated Games with Almost-Public Monitoring

Some private-monitoring games, that is, games with no public histories, can have histories that are almost public. These games are the natural result of perturbing public monitoring games towards private monitoring. We explore the extent to which it is possible to coordinate continuation play in such games. It is always possible to coordinate continuation play by requiring behavior to have bounded recall (i.e., there is a bound L such that in any period, the last L signals are sufficient to determine behavior). We show that, in games with general almost-public private monitoring, this is essentially the only behavior that can coordinate continuation play.repeated games, private monitoring, almost-public monitoring, coordination, bounded recall

Repeated Games with Almost-Public Monitoring

In repeated games with imperfect public monitoring, players can use public signals to coordinate their behavior perfectly, and thus support cooperative outcomes with the threat of punishments. But with even a small amount of private monitoring, players' private histories may lead them to have sufficiently different views of the world that such coordination on punishments is no longer possible (we describe a simple strategy profile that is a perfect public equilibrium of a repeated prisoner's dilemma with imperfect public monitoring, and yet is not an equilibrium for arbitrarily close games with private monitoring). If a perfect public equilibrium has players' behavior conditioned only on finite histories, then it induces an equilibrium in all close-by games with private monitoring. This implies a folk theorem for repeated games with almost-public almost-perfect monitoring.

Risk Management for Nonprofits

Our research, based on the first comprehensive financial analysis of New York's nonprofit sector, found that 10% of the city's nonprofits were insolvent and 40% had virtually no cash reserves. Less than 30% were financially strong. If anything, things are getting harder, given market volatility, the move to value-based payments in health care, and increased costs for real estate and labor.Fortunately, we also discovered that nonprofits can take a few concrete steps to reduce their risk of failure and sustain vital programs:Make risk management an explicit responsibility of the audit and/or finance committee.Develop a risk-tolerance statement, indicating the limits for risk-taking and the willingness to trade short-term impact for longer-term sustainability.Keep a running list of major risks and the likelihood and expected loss for each.Put in place plans for how to maintain service in the event of a financial disaster, or even a "living will" that specifies how programs will be transferred to other providers (or wound down in an orderly fashion) in the event that recovery is not possible.Brief trustees regularly about longer-term trends in the operating environment.Periodically explore the potential benefits of various forms of organizational redesign, such as mergers, acquisitions, joint ventures, partnerships, outsourcing, managed dissolutions, and divestments.Compare financial performance to peers on an annual basis.Develop explicit targets for operating results (margins, months of cash, etc.) and contingency plans if minimum targets are not met.Redouble efforts to build and safeguard a financial cushion or "rainy-day fund," even if doing so forces consideration of difficult programmatic trade-offs.Doing any of these will depend on a functioning partnership between capable management and a critical mass of experienced, educated and engaged board members. Therefore, organizations serious about risk management must work hard to recruit board members with a wide range of experience. They need to ensure ongoing education for both new and existing board members and to empower high-functioning committees. Many organizations, particularly large and complex ones, would also benefit from having an experienced nonprofit executive on their board

A Foundation for Markov Equilibria in Infinite Horizon Perfect Information Games

We study perfect information games with an infinite horizon played by an arbitrary number of players. This class of games includes infinitely repeated perfect information games, repeated games with asynchronous moves, games with long and short run players, games with overlapping generations of players, and canonical non-cooperative models of bargaining. We consider two restrictions on equilibria. An equilibrium is purifiable if close by behavior is consistent with equilibrium when agents’ payoffs at each node are perturbed additively and independently. An equilibrium has bounded recall if there exists K such that at most one player’s strategy depends on what happened more than K periods earlier. We show that only Markov equilibria have bounded memory and are purifiable. Thus if a game has at most one long-run player, all purifiable equilibria are Markov.Markov, bounded recall, purification