From the U.S. Department of Agriculture:
Organic Farmgate and Wholesale Prices. USDA Economic Research Service (ERS).
"This data set provides farmgate and wholesale prices for select organic and conventional produce items for the Boston and San Francisco markets. Prices are based on those reported by USDA Agricultural Marketing Service Market News reports for 1995-2004 (wholesale prices), Organic Food Business News for 2000-04 (organic farmgate prices), and USDA National Agricultural Statistics Service as reported in ERS Vegetables and Melons Yearbook (conventional farmgate prices). May 27, 2005"
Organic Production. USDA Economic Research Service (ERS).
"Data page providing information on organic operations and acreage for crops and livestock for 1992-2003. October 14, 2002"
Briefing Room: Organic Farming and Marketing. USDA Economic Research Service (ERS).
State Marketing Profiles. USDA Agricultural Marketing Service (AMS).
"State in Brief" reports include basic organic sales and acreage data; "Organic Agriculture" portion identifies state contacts and USDA-accredited certifying agents.
Fruit and Vegetable Marketing News. USDA Agricultural Marketing Service (AMS).
Many "Terminal Market Reports" contain price information for organic produce. Try a search on the Portal page for "organic;" then use the "find on this page" browser function to find the references of interest.
2002 Census of Agriculture. USDA National Agricultural Statistics Service (NASS).
Certified organic commodities were covered in the 2002 census. See: "Table 2. Market Value of Agricultural Products Sold Including Landlord's Share, Direct, and Organic: 2002 and 1997" under U.S. Summary and State Reports and State and County Reports.
U.S. Market Profile Organic Foods. USDA Foreign Agriculture Service (FAS).
2005 report includes U.S. market and consumption figures.
Attaché Reports. USDA Foreign Agriculture Service (FAS).
Reports specific to organic, by country. Regional and country market and production data are often cited.
Other U.S. Sources:
A View from Space: The Community of U.S. Organic Farmers, 2006. Organic Farming Research Foundation (OFRF).
Map showing the distribution of certified organic producers from the USDA National Organic Program's most recent organic producer list.
Organic Facts. Organic Trade Association (OTA).
Section points to market and food data and reports. See especially "Market Trends."
Organic Price Index (OPX®). New Farm.
Statistics on Organic Agriculture. Washington State University.
Web portal/clearinghouse for data from the Northwest, California and USDA.
The Status of Organic Agriculture in Minnesota - A Report to the Legislature: 2006. Minnesota Department of Agriculture.
The Status of Organic Agriculture in North Dakota: December 2005. North Dakota Department of Agriculture
Organic Agriculture in Wisconsin: 2005 Status Report. University of Wisconsin-Madison, February, 2006.
Organic Statistics for Canada and by Province. Canadian Organic Growers.
Certified Organic Production in Canada 2005, prepared for Canadian Organic Growers by Anne Macey, August 2006. 38p.
Organic-Europe. Research Institute of Organic Agriculture FiBL.
Country reports and Current European organic farming statistics, links
The World of Organic Agriculture 2006: Statistics and Emerging Trends. 8th revised edition. IFOAM, February 2006.
Whole report available for purchase. The chapter "Current Status of Organic Farming World-Wide" summarizing the main results and the global organic statistics can be downloaded free of charge at www.orgprints.org/5161
International Trade Center: Organic Link. UNCTAD/WTO.
Links to market studies/ data ("Market Research") and country studies.
For a sampling of commercial market reports that the organic food industry managers are looking at (and paying a lot of money for), see report titles, abstracts and prices available via FoodNavigator: http://www.foodnavigator.com/marketreport/results.asp?c=505&n=1&o=DateDesc