Since “rents attract rent-seekers” (Goodman 2004, 8), economic rents are among the incentives that prompt conventional farmers to turn to organic agriculture. Since economic rents are subject to reduction through competition, they can be “either eroded, appropriated, or passed through to land values” (Guthman 2004b, 513), or organic certification standards can “create a barrier to entry so formidable that all of the rent income earned by market entry is spent in scaling the barrier” (Mutersbaugh 2005, 2040). Thus, economic rents from organic certification are not guaranteed, but are possible. However, political economists have made little effort to demonstrate these economic rents empirically, which leaves the wide variation in the profitability of organic farms (cf. Offermann and Nieberg 2000) largely unexplained.