Computer Model Development
In the late 1990s, Mr. Shefftz managed the initial development of the Windows operating system versions of the BEN, PROJECT, ABEL, INDIPAY, and MUNIPAY computer models. The U.S. Environmental Protection Agency's Office of Enforcement and Compliance Assurance applies these models to financial economics issues in environmental enforcement actions. Additional information on these models is available here:
Mr. Shefftz has also prepared the models’ help systems and training materials, as well as presented training courses and provided related support for federal and state enforcement staff. He delivered training courses on the models, both in-persona and via webinars.
Mr. Shefftz continues to work on the revisions to these models (via a subcontract with IEc), including both the periodic updates to the models' internal financial databases and other improvements based in part upon user base feedback. He has also created versions of these models for other nations, including Canada, Chile, and El Salvador.
These models employ a Visual BASIC graphical user interface with an ActiveX control to run a Microsoft Excel spreadsheet in the background. The user does not need to know how to use Excel, or even need to have Excel installed on the computer, in order to run the models.
With such an arrangement, all the computational aspects of a model can be developed cost-effectively within Excel. The graphical user interface can usually be copied in large part from previously developed models. This allows the development of a standalone computer application for little more than the cost of creating a simple spreadsheet.
For example, for the U.S. Department of Justice Commercial Litigation Branch, Mr. Shefftz developed a standalone computer application to calculate statutorily determined interest accruing on damages claims under the Contract Disputes Act. For a state agency, he developed a model to calculate the net present value of future remediation costs. For U.S. EPA’s Office of Site Remediation and Enforcement, Mr. Shefftz developed a model to assess the combined affordability of financial assurance and cleanup costs.