Considering Aquacultural Externality in Coastal Land Allocation Decisions in India

Commercial aquaculture in India has come under attack for having caused negative agricultural and environmental impacts. This paper formulates an interactive model of non-renewable and renewable resources to characterize land allocations between aquaculture and agriculture in ecologically and economically sustainable fashion. Through an empirical application, various economic and policy circumstances that affect the optimal land allocation mix are evaluated. The aquaculture industry must address two economic effects: off-site negative effects on renewable food and other coastal resources, and on-site self-pollution of shrimp ponds. Current regulatory and land-use policies are inadequate to address these effects.     

De Industrieele „Trusts” der Vereenigde Staten van noord-Amerika

November 19015 December     

北极冰川融化影响几何？

北极冰川融化将使跨北极通航成为可能，运输公司可减少40％的航运距离。马六甲海峡也将不再垄断国际通运。国际经济将进一步融合。     

Playing for Your Own Audience: Extremism in Two‐Party Elections

This paper considers a two‐party election with a single‐dimensional policy space. We assume that each voter has a higher probability of observing the position of the party he is affiliated with than the position of the other party, an assumption that is consistent with the National Election Studies (NES) electoral data set. In equilibrium, the two parties locate away from the median, because the voters who dislike a party's platform observe its policy choice with a lower probability, and its own audience like policy choices that cater to its taste. As the asymmetry in voter information or the cost of voting increases, the parties adopt more extreme platforms, while if there are fewer extreme voters the opposite effect occurs. Making voters more symmetrically informed about the two parties' platforms increases the welfare of society, while asymmetric information acquisition by the voters is worse than no information acquisition at all.     

On Conditional Density Estimation

With the aim of mitigating the possible problem of negativity in the estimation of the conditional density function, we introduce a so-called re-weighted Nadaraya-Watson (RNW) estimator. The proposed RNW estimator is constructed by a slight modification of the well-known Nadaraya-Watson smoother. With a detailed asymptotic analysis, we demonstrate that the RNW smoother preserves the superior large-sample bias property of the local linear smoother of the conditional density recently proposed in the literature. As a matter of independent statistical interest, the limit distribution of the RNW estimator is also derived.     

Demographic and Economic Pressure on Emigration out of Africa*

Two of the main forces driving European emigration in the late nineteenth century were real wage gaps between sending and receiving regions and demographic booms in the low‐wage sending regions. Our new estimates of net migration for the countries of sub‐Saharan Africa show that exactly the same forces driving African across‐border migration are at work today. The results suggest that rapid growth in the cohort of potential young emigrants, population pressure on the resource base, and slow economic growth are likely to intensify the pressure for migration out of Africa and into high‐wage OECD countries over the next two decades.     

Non‐linear Predictability of UK Stock Market Returns*

Linear predictability of stock market returns has been widely reported. However, recently developed theoretical research has suggested that due to the interaction of noise and arbitrage traders, stock returns are inherently non‐linear, whereby market dynamics differ between small and large returns. This paper examines whether an exponential smooth transition threshold model, which is capable of capturing this non‐linear behaviour, can provide a better characterization of UK stock market returns than either a linear model or an alternate non‐linear model. The results of both in‐sample and out‐of‐sample specification tests support the exponential smooth transition threshold model and hence the belief that investor behaviour does differ between large and small returns.     

Additive and Multiplicative Uncertainty Revisited: What Explains the Contrasting Biases?

above the certainty level while for additive uncertainty the price should be lower than the certainty level. This note gives an intuitive explanation for the result after first presenting a parsimonious review of the two models. We also discuss which, if either, of the two models is more realistic. Received December 14, 2001; revised version received July 16, 2002 Published online: April 30, 2003 We thank referees for helpful comments. Ciaran Driver would like to acknowledge the research facilities from ANU, Canberra for their help in writing this paper.