本文的主要内容是PPP模型的评价，在外部冲击的背景下，两种比较流行的方法是使用购买力平价和Salter-Swan方法(Devarajan, et al.， 1993)。现在PPP在理论和实践上都更加稳定，而Salter Swan模型更适合在进出口不完全替代的情况下使用。PPP比模型要小，模型提供了更丰富的方法来计算外国资本流入和冲击交换。然而，购买力平价仍然很简单，统计活动较少，导致市场能够更好地适应冲击。本篇爱丁堡论文代写文章由英国论文通AssignmentPass辅导网整理，供大家参考阅读。
In the context of external shocks, two of the more popular approaches are the use of the PPP purchasing power parity and the Salter-Swan approach (Devarajan, et al., 1993). Now the PPP is more theoretically and practically stable and the Salter Swan model is more proper for using in the context of imperfect substitutes for imports and exports. The PPP is less than the model in the way, the model offers for much richer way of calculating foreign capital inflows and the shock exchanges. However, the PPP remains simple, and with less statistical activities leading the market to a better convergence with the shock.
Now the advantages of using the PPP in such exchange rate determination is that the PPP determined exchange rates when adopted by all nations would actually make the exchange rate more stable. Market based rates however are more volatile and hence it could be said to swing high or low (Muscatelli and Spinelli, 1999). Market based rates give more emphasis to the international comparison, but might fail to take into account the labour prices of the country, purchasing power and more in the context of their overall welfare. PPP is better suited as a tool to understand the general wellbeing of a country.
Now a con of PPP has to be considered before positively advocating for it is that of how PPP might be difficult to measure as compared to other market based rates. The use of ICP with PPP would definitely be a positive undertaking. However, it is not a very practical or feasible undertaking when considered in the context of all nations of the world. It is a huge statistical undertaking and PPP rates have to be determined in very methodical way at significant interval of times that furthermore would make the whole process rather cumbersome. Now despite the setbacks and despite the fact that such assessments could introduce some inaccuracies, the fact remains that they would absorb shocks better and could bring about a slow rate of convergence.
Testing PPP in a univariate framework aimed at understanding the real shocks of Norway indicates that there is a clear convergence in PPP towards the medium run. The half-life in deviation from parity will be around one and half years. It is furthermore observed that the Norwegian countries real exchange rate is not affected here, “In addition, the Norwegian equilibrium real exchange rate appears to have been constant over the sample period. We also find that deviations from parity are mostly corrected by adjustment of the nominal exchange rate; the contribution of domestic prices appears to be weak and ambiguous. This suggests that in the long run the direction of causation is from domestic prices to the nominal exchange rate” (Qaisar, 2002, p.27).