Mathys, Nicole

2008, Grether, Jean Marie, Mathys, Nicole, de Melo, Jaime

A growth-decomposition (scale, technique and composition effect) covering 62 countries and 7 manufacturing sectors over the 1990-2000 period shows that trade, through reallocations of activities across countries, has contributed to a 2-3 percent decrease in world SO2 emissions. However, when compared to a constructed counterfactual no-trade benchmark, depending on the base year, trade would have contributed to a 3-10 percent increase in emissions. Finally adding emissions coming from trade-related transport activities, global emissions are increased through trade by 16 percent in 1990 and 13 percent in 2000, the decline being largely attributable to a shift of dirty activities towards cleaner countries.

2007, de Melo, Jaime, Grether, Jean-marie, Mathys, Nicole

Combining unique data bases on emissions with sectoral output and employment data, we study the sources of the fall in world-wide SO2 emissions and estimate the impact of trade on emissions. Contrarily to concerns raised by environmentalists, an emission-decomposition exercise shows that scale effects are dominated by technique effects working towards a reduction in emissions. A second exercise comparing the actual trade situation with an autarky benchmark estimates that trade, by allowing clean countries to become net importers of emissions, leads to a 10% increase in world emissions with respect to autarky in 1990, a figure that shrinks to 3.5% in 2000. Additionally, back-of-the-envelope calculations suggest that emissions related to transport are of smaller magnitude, roughly 3% in both periods. In a third exercise, we use linear programming to simulate extreme situations where world emissions are either maximal or minimal. It turns out that effective emissions correspond to a 90% reduction with respect to the worst case, but that another 80% reduction could be reached if emissions were minimal.