1.91 Ocean ecosystems and the environmental and human impact on fish stocks, however, are very complex and are only partially understood. As a result, fisheries science is a challenge and reflects significant uncertainties over most years, including the assessment of fish stocks and expected conservation outcomes. A detailed table of international environmental agreements, to which the EU is already a party or signatory, has been drawn up. We have selected the following five international environmental agreements as an audit case study: 26When one country uses a cap-and-trade system and the other applies a tax, trade takes place (if so) when the equilibrium price of autarchy for caps and trade authorizations is different from the tax. If the price of the autarky authorization is less than the tax, the ceiling and export of the commercial country are allowed. In this case, there is a gain in efficiency and a reduction in emissions. Emissions remain stable in the tax-burden country, as the marginal costs of producers (the tax) have not changed; but emissions are decreasing in the country of cape and trade, because that country exports part of its emission permits. In addition, tax revenues are declining in the country subject to tax constraints. However, if the price of the authorization of the autarchy is higher than the tax, the ceiling and the trading country are imported from the country collecting the tax until the authorization price falls to the level of tax. In this case, trade increases tax revenues in the country subject to fiscal constraints and reduces the rents of quotas in the country of cape and trade. Worse still, trade undermines environmental legislation in cape and trade countries, resulting in a net increase in emissions. These examples show that a free exchange of permits can easily undermine environmental policy if policies are not harmonized in different countries. Since trade in authorizations is also implicit in trade in goods, trade in the latter trade can also undermine environmental policy – a point that has already been raised in Section 2 of the project.
It should be noted that these remarks relate to global (or cross-border) environmental problems such as those in the case of greenhouse gases. If pollution remains within national borders, trade considerations are (relatively) insignificant. 18The qualitative conclusion that taxation is more efficient than heading and trade is quite robust compared to changes in parametric values. However, these results are based on strong assumptions about functional forms of mitigation costs and environmental damage, particularly the assumption that uncertainties do not affect the slope of marginal cost and profit curves. The results are not robust for generalizations in terms of functional form, and for this reason, they are more valuable as a source of intuition than as a basis for categorical advice. A more complex policy, for example. B an optimal two-part tax (ceiling and trade with a price cap), could of course dominate either tax policies or cap-and-trade policies. Although taxation is a more effective way to reduce greenhouse gases (Nordhaus 2007), policy considerations could make a cap and trade policy a more practical alternative (Stavins 2008).