Takayama and Judge introduced the price endogenous mathematical programming model as an alternative to the traditional econometric approach to sector-level policy analysis. McCarl and Spreen provided a review of price endogenous mathematical programming models. In that paper, they showed how price endogeneity can be introduced into a standard firm-level linear programming model. The introduction of price endogeneity allows expansion of the firm-level specification to a market-level analysis. At the time of publication of McCarl and Spreen, however, the application of price endogenous mathematical programming models was limited by the availability of software packages that could directly solve such models. The typical application used linear supply and/or demand relationships, which resulted in a quadratic programming (QP) specification. The advent of MINOS in the 1980s and then its incorporation into GAMS has lifted the computation constraint. In the present day, numerous price endogenous models have been developed. I can lay claim to six such models.

Although opportunities and challenges for the Cooperative Extension Service have been addressed in the agricultural economics literature, little attention has been paid to the extension scholar. This article relates Boyer's scholarship concepts and subsequent scholarship assessment articles to agricultural economics extension and describes some unique features of the extension scholar's operating environment. Organizational framework, leadership, staffing, funding, accountability, and evaluation are addressed. Data from a survey of agricultural economics department heads are used to supplement personal experience in describing the current operating environment and constraints for extension scholars.

This study examines the relationship between urban forests and household income and population density in the 149 cities with populations over 40,000 in nine southeastern states. Our empirical results show that urban forest percentage across the cities has characteristics of the environmental Kuznets curve. We find that household income around $39,000 is a threshold that changes the relationship between income and urban forest coverage from negative to positive, whereas the impact of population density on urban forests is just the opposite, from positive to negative when population density is around 180 persons per square kilometer.

This study estimates the effects of an urban growth boundary (UGB) on land development decisions in Knox County, TN, using a heteroscedastic probit model. With combined effects of increased land development within the city boundary and decreased development within the UGB and the neighboring town of Farragut after the implementation of UGB, the UGB of Knox County has been successful in urban revitalization within the city boundary and discouraging urban sprawl. These UGB impacts may be related to the city government having the right to annex land parcels within the UGB without consent of land owners.

A two-stage multinomial logit selection model is used to model the relationship between demographic characteristics and housing density across Tennessee's six metropolitan statistical areas. The study finds that there is both spatial correlation and heterogeneity in the spatial distribution of housing both within and across the six areas. For example, Memphis, the most densely populated area, has the least amount of spatial correlation among housing density at the neighborhood level, while Johnson City, which has the lowest overall housing density, has the highest degree of spatial correlation.

This paper explores the influence of demographic and spatial variables on individual participation and consumption of wildland area recreation. Data from the National Survey on Recreation and the Environment are combined with geographical information system-based distance measures to develop nonlinear regression models used to predict both participation and the number of days of participation in wilderness and primitive area recreation. The estimated models corroborate previous findings indicating that race (black), ethnicity (Hispanic), immigrant status, age, and urban dwelling are negatively correlated with wildland visitation, while income, gender (male), and education positively affect wild-land recreation participation and use. The presence of a distance or proximity factor mitigates some of the influence of race and ethnicity. The results of the cross-sectional models are combined with U.S. Census projections of total population, changes in population characteristics, and estimates of current National Forest Wilderness visitation estimates to give some insight into pressure that might be expected on the nation's designated wilderness during the next half century. Results generally indicate that per-capita participation and visitation rates will decline over time as society changes. Total wilderness participation and visitation will, however, increase, but at a rate less than population growth.

We examine the economic tradeoff between the costs of pre-event preparedness and post-event response to the potential introduction of an infectious animal disease. In a simplified case study setting, we examine the conditions for optimality of an enhanced pre-event detection system considering various characteristics of a potential infectious cattle disease outbreak, costs of program implementation, severity of the disease outbreak, and relative effectiveness of postevent response actions. We show that the decision to invest in pre-event preparedness activities depends on such factors as probability of disease introduction, disease spread rate, relative costs, ancillary benefits, and effectiveness of mitigation strategies.

The growing movement of people and goods that started in the closing years of the twentieth century has increased the possibility of the accidental or intentional introduction of biohazards that can affect agricultural production in the United States. This study examines the ex ante decision between the deployment of monitoring devices (traps) versus the use of countermeasures to control Mediterranean fruit flies in Florida. To examine this tradeoff, this study outlines a mathematical model to study the effectiveness of traps and the cost of treatment. The empirical results presented in this study indicate that additional parameterization efforts are needed.

Both papers in this session illustrate a growing trend among agricultural economists to let go of their comfort zones and move beyond the bounds of the traditional market analysis and a world of certainty into the less familiar and more challenging world of uncertainty. This trend augurs well for the profession and demonstrates the imperialistic tendency of economics to deal with all kinds of issues.

Exotic and invasive species and bioterrorism are of increasing concern for U.S. policy makers. The economic analysis of these issues, especially bioterrorism, is a fast-growing, relatively new area. It is an area where an economist can provide important input into both policy and applied theory. The two papers in this section address invasive species issues.