scientific methods, economist Robert Fogel noted Kuznets's own reservations about the "fragility of the data" which underpinned the hypothesis. Fogel notes that most of Kuznets's paper was devoted to explicating the conflicting factors at play. Fogel emphasized Kuznets's opinion that "even if the data turned out to be valid, they pertained to an extremely limited period of time and to exceptional historical experiences." Fogel noted that despite these "repeated warnings", Kuznets's caveats were overlooked, and the Kuznets curve was "raised to the level of law" by other economists. Inequality and trade liberalization Dobson and Ramlogan's research looked to identify the relationship between inequality and trade liberalization. There have been mixed findings with this idea – some developing countries have experienced greater inequality, less inequality, or no difference at all, due to trade liberalization. Because of this, Dobson and Ramlogan suggest that perhaps trade openness can be related to inequality through a Kuznets curve framework. A trade liberalization-versus-inequality graph measures trade openness along the x-axis and inequality along the y-axis. Dobson and Ramlogan determine trade openness by the ratio of exports and imports (the total trade) and the average tariff rate; inequality is determined by gross primary school enrolment rates, the share of agriculture in total output, the rate of inflation, and cumulative privatization. By studying data from several Latin American countries that have implemented trade liberalization policies in the past 30 years, the Kuznets curve seems to apply to the relationship between trade liberalization and inequality (measured by the GINI coefficient). However, many of these nations saw a shift from low-skill labour production to natural resource intensive activities. This shift would not benefit low-skill workers as much. So although their evidence seems to support the Kuznets theory in relation to trade liberalization, Dobson and Ramlogan assert that policies for redistribution must be simultaneously implemented in order to mitigate the initial increase in inequality. Environmental Kuznets curve The environmental Kuznets curve (EKC) is a hypothesized relationship between environmental quality and economic development: various indicators of environmental degradation tend to get worse as modern economic growth occurs until average income reaches a certain point over the course of development. The EKC suggests, in sum, that "the solution to pollution is economic growth." Although subject to continuing debate, there is considerable evidence to support the application of environmental Kuznets curve for various environmental health indicators, such as water, air pollution and ecological footprint