FARM-LEVEL EVALUATION OF ALTERNATIVE POLICY APPROACHES TO REDUCE NITRATE LEACHING FROM MIDWEST AGRICULTURE

Policies to reduce nitrate leaching are evaluated using a mixed integer linear programming model of a representative Michigan cash grain farm. At spring 1993 prices, elimination of the current deficiency payment program is found to be more efficient at reducing leaching than a nitrogen input tax, a tax credit on biologically fixed nitrogen, a rotation payment, or obligatory use of the Integrated Farm Management Program Option (IFMPO). However, elimination of the deficiency payment program would significantly reduce farm income. Modeling risk management and nitrate leaching dynamics are useful extensions of this research, as is estimating the benefits from averting nitrate leaching.Agricultural and Food Policy,

Evaluating the Long-run Impacts of the 9/11 Terrorist Attacks on US Domestic Airline Travel

Although the US airline industry began 2001 with 24 consecutive profitable quarters, including net profits in 2000 totaling $7.9 billion, the impact of the 9/11 event on the industry was substantial. Whereas the recession that began in early 2001 signaled the end of profitability, the 9/11 terrorist attacks pushed the industry into financial crisis after air travel dropped 20% over the September–December 2001 period compared to the same period in 2000. Given the decline in domestic air travel, an important question is whether the detrimental impact of the attacks was temporary or permanent. That is, did airline travel return to the trend that existed prior to the terrorist attacks? There are theoretical reasons to the believe that it would not. Economists have long viewed travel-mode choices as the outcome of a comparison of opportunity costs and benefits. Thus, anything that permanently raises the opportunity cost of travel, holding benefits constant, should reduce the level of travel volume. To determine whether air travel was permanently reduced, we use econometric and time-series forecasting models to generate a counter-factual forecast of air travel volume in the absence of the terrorist attacks. These dynamic forecasts are compared to actual air travel levels to determine the impact of the terrorist attacks. The findings suggest that domestic air travel did not return to the levels that would have existed in the absence of the attack

Non-equilibrium dynamic critical scaling of the quantum Ising chain

We solve for the time-dependent finite-size scaling functions of the 1D transverse-field Ising chain during a linear-in-time ramp of the field through the quantum critical point. We then simulate Mott-insulating bosons in a tilted potential, an experimentally-studied system in the same equilibrium universality class, and demonstrate that universality holds for the dynamics as well. We find qualitatively athermal features of the scaling functions, such as negative spin correlations, and show that they should be robustly observable within present cold atom experiments.Comment: 4 pages + 2 page supplemen

Using GIS to Evaluate the Effects of Flood Risk on Residential Property Values

Annually, flooding causes more property damage in the United States than any other type of natural disaster. One of the consequences of continued urbanization is the tendency for floodplains to expand, increasing flood risks in the areas around urban streams and rivers. Hedonic modeling techniques can be used to estimate the relationship between residential housing prices and flood risks. One weakness of hedonic modeling has been incomplete controls for locational characteristics influencing a given property. In addition, relatively primitive assumptions have been employed in modeling flood risk exposures. We use GIS tools to provide more accurate measures of flood risks, and a more thorough accounting of the locational features in the neighborhood. This has important policy implications. Once a complete hedonic model is developed, the reduction in property value attributed to an increase in flood risks can, under certain circumstances, be interpreted as the household’s willingness to pay for the reduction of flood risk. Willingness to pay estimates can in turn be used to guide policymakers as they assess community-wide benefits from flood control projects