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MARK RIBAS is the President and Director of Pennsylvania Tax Institutes, Inc. He retired in 2012 from his position as an Internal Revenue Agent after 38 years with the IRS. Mark, a CPA licensed in the state of West Virginia, has taught the Land Grant University Tax Seminar for West Virginia University, Virginia Tech, and Texas A&M University. He has also served as an adjunct professor of accounting for Fairmont State University and presented at several Tax Executive Institute and Working Together conferences.

SUSAN HARPER is also an officer of Pennsylvania Tax Institutes, Inc. Susan has over 30 years of experience at the IRS as an Internal Revenue Agent. Susan is currently serving as a Fraud Technical Advisor who specialized in examinations of abusive tax transactions prior to her current position. She has also instructed the Land Grant University Tax Seminars for West Virginia University, Virginia Tech, and Texas A&M since 2000.

PHILIP G. YAMALIS represents the IRS at educational and taxpayer outreach events working with tax professionals, payroll providers, industry and trade associations, small business owners, as well as in conjunction with other Federal, State and local government agencies. Philip’s responsibilities have included working with the practitioner community to increase awareness of Abusive Tax Avoidance Transactions, as well as working with various Small Business industry organizations to promote voluntary compliance.  He is a certified IRS instructor, and represents the IRS at various practitioner CPE sessions in Western PA and West Virginia.

GUIDO VAN DER HOEVEN joins us from Iowa State University Center for Agricultural Law & Taxation where he is an Agricultural Tax Specialist. Guido was previously an Extension Specialist/ Senior Lecturer, in the Department of Agricultural and Resource Economics at North Carolina State University in Raleigh, North Carolina prior to his retirement. Guido’s extension experience includes income taxation of individuals and business entities, farm business management and the profitable continuation of "family firms" to succeeding generations. Van der Hoeven is an Enrolled Agent and presents income tax educational programming across the United States. He has over 40 years of experience in taxation with a focus on farming and natural resources issues. Van der Hoeven is President of the Land Grant University Tax Education Foundation, Inc. which publishes a ~700 page text for income tax training of professional tax practitioners. Guido van der Hoeven holds a B.S. in Natural Resource Management – Soils and a M.S. in Agricultural Economics from Kansas State University.

KRISTINE TIDGREN joins us from Iowa State University Center for Agricultural Law and Taxation where she is the Director. Kristine is also an adjunct assistant professor in the Agricultural Education & Studies Department. Her work focuses on studying and interpreting laws impacting the agricultural industry. In particular, she focuses on agricultural taxation. 

Since joining CALT in 2013, Kristine has written hundreds of articles and blogposts to keep tax professionals, practicing attorneys, producers, and agribusiness professionals informed about legal developments impacting their business. She also writes technical chapters for the National Income Tax Workbook and regular articles for farm publications. In addition to her writing, Kristine speaks to many professionals and producers each year regarding tax and agricultural law topics. She also plans and provides instruction for CALT-hosted seminars, including the annual federal income tax schools.

Kristine teaches AgEds 451, a four-credit agricultural law class to upper-level undergraduate students in the College of Agriculture and Life Sciences. She also regularly collaborates with other agricultural law and tax professionals throughout the country, including those from the Rural Tax Education Committee, the American Agricultural Law Association, and the Land Grant University Tax Education Foundation. Kristine is licensed to practice law in Iowa and Missouri and is a member of the Iowa Bar Association. Before joining to ISU, Kristine worked for a legal publishing company and as a practicing attorney. She received her J.D., Order of the Coif, from the University of Texas at Austin and her B.A. in journalism from Iowa State. She grew up on a farm in west central Iowa.