Selected GAMS and or Optimization Projects Done by Bruce McCarl

Selected GAMS and or Optimization Projects Done by Bruce McCarl

Project Focus -- Sector model of US Agricultural Sector
Type of Model -- Price endogenous nonlinear model of US Agricultural Sector for 70+ commodities in 63 US regions, versions include stochastic yields and world trade in seven commodities among 36 groups of countries
Rough Model Size -- Version have in excess of 100,000 variables , 300 of which are nonlinear and 15,000 constraints
Notes on Usage -- Model has been in heavy use for more than 20 years. Has been used to study effects of climate change, greenhouse gas mitigation, El Nino forecasting, conservation tillage, new cropping technology, pesticide bans and farm program revisions among numerous other applications. Related models have been built in Mali, Kenya, Egypt, Jordan, Guyana, and Nicaragua

Project Focus -- Analysis of Water Allocation between Municipal, Industrial and Agricultural water users for the Edwards Aquifer Near San Antonio, Texas examining effects of allocation schemes on water prices, incomes, water use by party, pumping lift, aquifer elevation and spring flow under uncertain aquifer recharge
Type of Model -- Price endogenous, nonlinear, stochastic programming with recourse, risk model
Rough Model Size -- Has have in excess of 20,000 variables , 100 of which are nonlinear and 5,000 constraints
Notes on Usage -- Model has been in use for more than 10 years. Has been used to study effects of water marketing, critical year irrigation interruption, proposed water allocation rules, regional conjunctive management and farm program revisions among other applications

Project Focus -- A large state funded construction project was seeking the highest returning mix of securities in which to invest while meeting certain requirements for funding draws
Type of Model -- Mixed integer profit maximizing model
Rough Model Size -- Has in excess of 100 variables , 50 of which are integer and 40 constraints
Notes on Usage -- Model was used by a bank to design a set of securities that would give the highest ending cash level such that sufficient securities matured in each time period so that the draws could be met. Bank has set up an advertising brochure to model this capability to other project agencies. Integer variables assure instruments are bought in relevant units.

Project Focus --The possibility of reducing greenhouse gas emissions has stimulated activity regarding moving agricultural lands into forestry. This project evaluated the implications of such an effort
Type of Model -- Nonlinear price endogenous 90 year model of forest and agricultural sectors
Rough Model Size -- Has in excess of 100,000 variables and 30,000 constraints
Notes on Usage -- Model was used to show that countervailing land movements of forest deintensification would occur under such a policy. Model has been used by USEPA and Forest Service to evaluate a number of other questions.

Project Focus -- A meat packing plant was scheduled for a week to maximize multiple objectives regarding profitability and inventories on hand
Type of Model -- Mixed integer, multiple objective profit maximizing model
Rough Model Size -- Has in excess of 5000 variables , 250 of which are integer and 800 constraints
Notes on Usage -- Model was used to examine effects of revisions in plant operating policies and equipment inventories. Integer variables assure non interference of products in smokehouses.

Project Focus -- A potential set of dams were appraised in terms of the economic benefits and environmental implications of their use for salinity control in the Red River
Type of Model -- Profit maximizing LP model
Rough Model Size -- Has in excess of 3000 variables and 400 constraints
Notes on Usage -- Model was used to appraise agricultural profits stimulated by project construction.

Project Focus --The Texas prison system stewards about 100,000 acres of land and uses agricultural product to feed 120,000 inmates. This study considered ways to improve management efficiency
Type of Model -- Profit maximizing model with some mixed integer variants
Rough Model Size -- Has in excess of 30,000 variables , and 7,000 constraints
Notes on Usage -- Model used by prison system to evaluate profitability of operation, and implications of altering agricultural management or inmate diet.

Project Focus -- A model was developed for direct farmer use in farm planning and machinery investment budgeting
Type of Model -- Linear Program
Rough Model Size -- Has in excess of 250 variables , and 140 constraints
Notes on Usage -- Model was used by Extension Service, machinery companies and farmers to do and assist in planning. Was used by more than 5,000 farmers.

Project Focus -- A milk coop wanted to study implications of coop reorganization and structure for prices of member milk and milk movement
Type of Model -- Linear profit maximizing model
Rough Model Size -- Has in excess of 20,000 variables , and 2,000 constraints
Notes on Usage -- Model was used to study alternative reconfiguration proposals.

Project Focus -- NOAA wished to generate data on the potential value of improved forecasting of El Nino events
Type of Model -- Price endogenous nonlinear model of US Agricultural Sector for 70+ commodities in 63 US regions, include stochastic yields from EL Nino and world trade in seven commodities among 36 groups of countries
Rough Model Size -- Has in excess of 50,000 variables ,and 10,000 constraints
Notes on Usage -- Model was used to generate appraisals of the Agricultural benefit of improved forecasting.

Project Focus -- Fossil fuel emission reduction may make it desirable to use renewable fuels. This study examined the cost of renewable fuel use and the environmental implications.
Type of Model --Nonlinear, price endogenous agriculture sector model
Rough Model Size -- Has in excess of 20,000 variables ,and 4,000 constraints
Notes on Usage --Model was used as input to Congressional deliberations regarding a biomass fuel initiative.