ST08 Projecting South Florida County-Level Citrus Acreage Using Time-Series Analysis (SAS(R) Automatic Forecasting System) and Multivariate Analysis (PROC FACTOR).     Contributed

Dr. Richard A. March
South Florida Water Management District
Abstract: The South Florida Water Management District has developed regional water supply plans for four planning areas within the South Florida area. These water supply plans are mandated by law (Section 373.0361, Florida Statutes). One component of these plans is conducting "(a) quantification of the water supply needs for all existing and reasonably projected future uses within the (20 year) planning horizon." Citrus irrigation is a major water use in South Florida; regional patterns of citrus acreage have changed substantially since the mid-1960’s, with a general southward movement of citrus associated with a series of freezes in the mid-1980’s. The approach taken in the Regional Water Supply Plans was to estimate citrus acreage in each county with a single equati on model. This paper presents alternative approaches to projecting citrus acreage using the SASŪ Automatic Forecasting System on a county-by-county basis and using PROC FACTOR to describe systematic relationships in citrus acreage in different counties. Po ssible extensions of the analysis using PROC SYSLIN and/or the newly released (Version 8.1) VARMAX procedure will also be discussed.

Biography:
Dr. Dick March has been an economist with the South Florida Water Management District in West Palm Beach, Florida since 1983. He has an A. B. in Economics from the College of William and Mary in Williamsburg, Virginia, and an M. S. and Ph. D. in Agricultur al Economics from Virginia Tech in Blacksburg, Virginia, where he started using SASŪ. His work at the the South Florida Water Management District involves forecasting urban and agricultural water demand, preparing Statements of Estimated Regulatory Cost fo r proposed District rules, and other economic and statistical analyses associated with the Comprehensive Everglades Restoration Program, Regional Water Supply Plans, and other economics/ planning-related activities of the water management district. He firs t used SASŪ (on punch cards) in 1974, but was away from SASŪ from 1983 until approximately 2000, when he began using SASŪ Version 8 through CITRIX. He works extensively with time-series analysis, using SAS/ETSŪ and also performs multivariate analysis and o