This year (2013), the City Club of Portland will be studying “Oregon’s Property Tax System.” The bibliography to that future report will be useful indeed.
In the meantime, here are some other Oregon Property Tax System reports to get you started:
1) Some counties provide useful summary information on Oregon’s Property Tax System.
2) Oregon Department of Revenue website, “How Property Taxes Work in Oregon.”
3) A 2009 Oregon Department of Revenue report, “A Brief History of Oregon Property Taxation.”
4) Oregon Legislative Revenue Office 1999 report on Oregon’s property tax system under Measure 50.