(CEECs).3 The gross agricultural output fell by between 15 and 30% for these countries between 1989 and 1992, although for both the Czech Republic and Slovenia, that followed a brief initial increase of some 10%. The decline subsequently moderated for these countries during the re­mainder of the 1990s and even reversed for the Czech Re­public, Poland and Hungary. For Albania, by 1998, output had even reached higher than the 1989 level by over 10% annually (Macours and Swinnen, 2000).
     Political and economic reform in Russia, republics of the Soviet Union and the Newly Independent States (NIS) of the 1990s produced similar consequences for agricultural productivity. Estimates for Russian crop production indi­cate a drop of 8% in productivity overall between 1993 and 1998, while overall agricultural productivity rose in Russia and Ukraine between 1992 and 1997 but only by 7% and 2% respectively (Liefert et al., 2002). The major changes in Russian agricultural production and trade following transi­tion included a halving of the livestock inventory resulting from a reduction in imports of animal feed. Fertilizer, ma­chinery and fuel use also fell substantially, resulting in cuts in domestic grain yields and harvest levels. The same applied to Ukraine as fertilizer output was switched to export sup­ply (Liefert et al., 2002).

2.3   Changes in Market Structure
Specialization in agricultural production has been accom­panied by significant changes in market structure for both agricultural inputs and outputs. Economic power in food and agriculture and thus the power to make decisions about what to produce and where to produce it, has moved to­ward fewer and fewer transnational firms which are em­bedded in a web of relationships in food production, from genetics to food retailing (Yoon, 2006). Some view these changes positively as a way to increase efficiency in the food system (Barkema et al., 2001) while others point toward increased marginalization of farmer and rural livelihoods and negative impacts on communities (Goldschmidt, 1978; Lobao, 2000; Stofferhan, 2006)
     In Europe, concentration in the food system started at the retail stage, becoming most obvious during the 1980s and 1990s (Vorley, 2003). In the US, concentration of own­ership and control became most visible in the production and processing stages, especially in the poultry sector in the mid-twentieth century. Contrary to European trends, in the US and Canada increased market share by fewer firms oc­curred in the agricultural input sectors and the food process­ing stage much earlier than in the food retailing sector.
     Horizontal integration is occurring at all stages of the food system from the genetics to raw agricultural commodi-
3 The countries that are included under the rubric of the CEEs differ. Some authors restrict the definition to the ten countries that underwent accession to the EU between 2004 and 2007, namely Estonia, Latvia, Lithuania, Poland, Romania, Slova­kia, Czech Republic, Hungary, Bulgaria and Slovenia. Others include Albania and the remaining Balkan states, but these are also referred to as the South East European Countries (SEEC). Most of the material here regards the CEEs as to the ten accession countries, unless other countries are referred to specifically.

ties to food retailing. The concentration ratio (CR4), which is a measure of the market share of the top four firms in a particular commodity, has continued to increase during the past decade in the US The largest four processors for all the major commodities now have from 50 to 80% of the mar­ket share (Table 2-3 and Figure 2-6) which can indicate de­creased competition in the marketplace forcing farmers into a relatively powerless position vis-à-vis suppliers or buyers. Others argue that competition is sufficient for farmers to obtain a fair price (Tweeten, 1992; MacDonald et al., 2000). Nevertheless, farmers across the NAE faced with decreasing choices buying agricultural inputs and selling outputs can face a cost-price squeeze that affects their ability to earn a livelihood from agriculture.
     The structure of the market for agricultural inputs has changed markedly in the last 50 years. For instance, two firms provide most of the fertilizer used today in North America while one firm has a 25% market share for fertil­izers in Europe. The seed industry is even more instructive for other inputs. Globally, the seed industry is increasingly driven by NAE based transnational agrifood businesses (UNCTAD, 2006). Four NAE-based transnational compa­nies provide almost 30% of the world's commercially avail­able seeds while NAE accounts for 43 % of the commercial seed market globally (Table 2-4).
     Many of the changes in NAE were anticipated by the changing nature of the US seed industry, the most heavily commercialized in the world. In the 1930s, over 150 com­panies formed to sell hybrid maize, but by the mid-1960s, American farmers had essentially abandoned open-pollinat­ed maize varieties with nearly all maize acreage planted to hybrid maize (Fernandez-Cornejo, 2004). Maize provided the kernel of transformation for the seed industry in general. Between 1970 and 2000, small private seed firms essentially vanished, with more than 50 acquisitions of seed firms by pharmaceutical  and  chemical  firms  (Fernandez-Cornejo, 2004). By the 1980s, the maize seed market was dominated by two firms and by the late 1990s, over 90% of cotton seed, 69% of maize seed and nearly half of soybean seeds were sold by the four largest firms in each crop. The same priva­tization trends are seen in Europe and as a consequence, the private sector is becoming increasingly important.
     One of the more striking features of industry changes in the last two decades has been the convergence of ownership between agrochemical and seed/genomic firms. This strat­egy has worked well "to better control and market proprie­tary lines of chemicals, genetic technologies and seeds, often sold in a single-bundled package" (UNCTAD, 2006). These bundles can be attractive to farmers and farmer managers as a purchased management tool. However, such packaged bundles can reduce flexibility of on-farm management strat­egies for pests and weeds, as well as implementation of novel consumer-driven production systems and increase reliance on purchased inputs (c.f. Hendrickson and James, 2005).
     When farmers sell their products, they also face highly concentrated markets. In the US less than 10 firms slaughter and process most of the broilers, turkeys, cattle (heifers and steers) and pork in the United States. Many of these are the same firms that operate in Canada. Moreover, the CR4 ratio has been increasing for all livestock processing—par­ticularly steers and heifers and hogs—since 1980 in the US.