Using Numerical Dynamic Programming to Compare Passive and Active Learning in the Adaptive Management of Nutrients in Shallow Lakes

This paper illustrates the use of dual/adaptive control methods to compare passive and active adaptive management decisions in the context of an ecosystem with a threshold effect. Using discrete-time dynamic programming techniques, we model optimal phosphorus loadings under both uncertainty about natural loadings and uncertainty regarding the critical level of phosphorus concentrations beyond which nutrient recycling begins. Active management is modeled by including the anticipated value of information (or learning) in the structure of the problem, and thus the agent can perturb the system (experiment), update beliefs, and learn about the uncertain parameter. Using this formulation, we define and value optimal experimentation both ex ante and ex post. Our simulation results show that experimentation is optimal over a large range of phosphorus concentration and belief space, though ex ante benefits are small. Furthermore, realized benefits may critically depend on the true underlying parameters of the problem.adaptive control, adaptive management, dynamic programming, value of experimentation, value of information, nonpoint source pollution, learning, decisions under uncertainty, Resource /Energy Economics and Policy,

The Fast Wandering of Slow Birds

I study a single "slow" bird moving with a flock of birds of a different, and faster (or slower) species. I find that every "species" of flocker has a characteristic speed $\gamma\ne v_0$, where $v_0$ is the mean speed of the flock, such that, if the speed $v_s$ of the "slow" bird equals $\gamma$, it will randomly wander transverse to the mean direction of flock motion far faster than the other birds will: its mean-squared transverse displacement will grow in $d=2$ with time $t$ like $t^{5/3}$, in contrast to $t^{4/3}$ for the other birds. In $d=3$, the slow bird's mean squared transverse displacement grows like $t^{5/4}$, in contrast to $t$ for the other birds. If $v_s\neq \gamma$, the mean-squared displacement of the "slow" bird crosses over from $t^{5/2}$ to $t^{4/3}$ scaling in $d=2$, and from $t^{5/4}$ to $t$ scaling in $d=3$, at a time $t_c$ that scales according to $t_c \propto|v_s-\gamma|^{-2}$.Comment: 10 pages; 5 pages of which did not appear in earlier versions, but were added in response to referee's suggestion

A Comparison of Methodologies for Valuing Decreased Health Effects from Wildfire Smoke

Wildfire seasons are becoming longer and more intense throughout the world, making it increasingly important to monetize the full damages caused by wildfires when analyzing various fire management policies. We estimate the economic costs of the health effects associated with exposure to wildfire smoke using a simple cost of illness approach and for the first time to our knowledge we estimate willingness-to-pay (WTP) for a decrease in symptom days from wildfire smoke using the contingent valuation method and the averting behavior method. Comparing estimates across all three common approaches for estimating the economic cost of exposure to an air pollutant is an important contribution to the literature. This study uses data from the largest wildfire in Los Angeles County’s modern history, the Station Fire of 2009. Our results show that a simple cost of illness estimate is about $3 per day of symptoms, the averting behavior method results in a WTP value of$43 or $94 to avoid one day of wildfire-smoke induced symptom days, depending on the model used, and the contingent valuation method results in a WTP estimate of$74 - $98 to avoid one day of wildfire-smoke induced symptom days, depending on model specification.averting behavior method, contingent valuation method, cost of illness, wildfire smoke, health, morbidity, Environmental Economics and Policy, Health Economics and Policy, Q,

Review of \u3ci\u3eKansas Politics and Government: The Clash of Political Cultures\u3c/i\u3e. By H. Edward Flentje and Joseph A. Aistrup.

Prior to the publication of Kansas Politics and Government, there was no essential book on Kansas politics, policy-making, and institutions. Now there is. It\u27s as simple as that. Anyone who wants to understand the Sunflower State\u27s politics should start here. Most prosaically, this is one more in the Nebraska Press\u27s ambitious series of single-state studies. But Ed Flentje and Joe Aistrup (disclaimer: I write a column for Kansas papers in rotation with them and two other political scientists) have done more than cover the breadth of the state\u27s politics. In their emphasis on political cultures, they provide an effective way to think about Kansas politics and government over almost 150 years of statehood

A procedure for assessing aircraft turbulence- penetration performance

Subsonic transport aircraft performance assessment during atmospheric turbulenc

IRRIGATION WATER DEMAND: A META ANALYSIS OF PRICE ELASTICITIES

Meta-regression models are estimated to investigate sources of variation in empirical estimates of the price elasticity of irrigation water demand. Elasticity estimates are drawn from mathematical programming, econometric and field experiment studies reported in the United States since 1963. Explanatory variables include method of analysis, water price, time-frame of analysis, farmers' adjustment options, type of data, and climate. Results indicate that the magnitudes of elasticity estimates are affected by the method of analysis. When separate regressions are performed for the estimates from each method, the price of water at which an elasticity is estimated as well as the time-frame of analysis are found to influence price elasticities.Resource /Energy Economics and Policy,