Optimisation of water procurement decisions in an irrigation district: the role of option contracts

Water supply instability is one of the main risks faced by irrigation districts and farmers. Water procurement decision optimisation is essential in order to increase supply reliability and reduce costs. Water markets, such as spot purchases or water supply option contracts, can make this decision process more flexible. We analyse the potential interest in an option contract for an irrigation district that has access to several water sources. We apply a stochastic recursive mathematical programming model to simulate the water procurement decisions of an irrigation district's board operating in a context of water supply uncertainty in south‐eastern Spain. We analyse what role different option contracts could play in securing its water supply. Results suggest that the irrigation district would be willing to accept the proposed option contract in most cases subject to realistic values of the option contract financial terms. Of nine different water sources, desalination and the option contract are the main substitutes, where the use of either depends on the contract parameters. The contract premium and optioned volume are the variables that have a greater impact on the irrigation district's decisions.     

Firm-Level Evidence on International Stock Market Comovement *

We explore the link between international stock market comovement and the extent to which firms operate globally. Using stock returns and balance sheet data for companies in 20 countries, we estimate a factor model that decomposes stock returns into global, country-and industry-specific shocks. We find a large and statistically significant link for global shocks. A firm raising its international sales by 10 percent raises the exposure of its stock return to global shocks by two percent. This link has grown stronger over time since the mid-1980s. We find no similarly robust link between international sales and exposure to country-specific shocks. * We are grateful to Marcelle Chauvet, Kathryn Dominguez, Kristin Forbes, Geert Rouwenhorst, Dan Waggoner, participants in the Atlanta Fed Finance Brown Bag, the IMF conference on “Global Linkages”, and the Kiel Institute for World Economics workshop on multinationals for their suggestions. We are especially grateful to Franklin Allen, Marco Pagano, and two anonymous referees for extensive comments on earlier drafts of this paper. Finally, we wish to thank Menzie Chinn for sharing his capital account liberalization measure, Iskander Karibzhanov for translating some of our code into C and Young Kim for excellent research assistance.     

Effects of Using Mean Scores in Regression Models: An Example From Environmental Psychology

Multiple regression analysis with grouped data is often used as a method for exploring environmental preferences, the preferred unit for measurement in such analyses is mean scores rather than individual scores.Although this procedure allows us to reduce the potential for error in measuring different variables and, as a consequence of this, improves the reliability of the technique, it also produces some additional, undesirable effects. The latter include artificial increases in R² values which give the impression that a high degree of fit has been achieved for the regression model. Indeed, this goodness fit often appears to be better than that which could have been achieved by using individual scores. Further, given that different studies operate with differing numbers of subjects in their groups, the R² scores which result from the analyses of these groups are not directly comparable.In the following discussion, we demonstrate how any value, other than zero for correlations between variables, can be increased, at will, by simply expanding the number of subjects in each group. We present the specialised formulae used for quantifying this increase and offer a warning about the purely relative nature of any study which bases its conclusions on models of regression analysis using grouped data.     

RARE SHOCKS,GREAT RECESSIONS

We estimate a DSGE (dynamic stochastic general equilibrium) model where rare large shocks can occur, by replacing the commonly used Gaussian assumption with a Student's t‐distribution. Results from the Smets and Wouters (American Economic Review 2007; 97 : 586–606) model estimated on the usual set of macroeconomic time series over the 1964–2011 period indicate that (i) the Student's t specification is strongly favored by the data even when we allow for low‐frequency variation in the volatility of the shocks, and (ii)) the estimated degrees of freedom are quite low for several shocks that drive US business cycles, implying an important role for rare large shocks. This result holds even if we exclude the Great Recession period from the sample. We also show that inference about low‐frequency changes in volatility—and, in particular, inference about the magnitude of Great Moderation—is different once we allow for fat tails. Copyright © 2014 John Wiley & Sons, Ltd.     

Local Labor Supply Responses to Immigration

How natives adjust is central to an understanding of the impact of immigration in destination countries. Using detailed labor force data for Malaysia for 1990–2010, we provide estimates of native responses to immigration on multiple extensive margins and rare evidence for a developing country. Instrumental variable estimates show that increased immigration to a state causes substantial internal inward migration, consistent with the fact that immigration increases the demand for native workers. Relocating Malaysian workers are accompanied by their spouses (three‐quarters of whom are housewives) and children who attend school. We find that these effects are concentrated among middle‐ and lower‐skilled Malaysians.     

A Comparison of Residents' Perceptions in Two Cruise Ports in the Mediterranean Sea

This paper examines residents' perceptions of a wide set of externalities exerted by the development of cruise tourism. The research involved data collection in two ports located in the two largest Mediterranean islands, Sicily and Sardinia, during the summer peak of the cruise season 2011. These two cruise destinations are especially interesting as they are characterized by a distinct life cycle. The empirical findings show that the two groups of residents have statistically equal perceptions on cruise activity in their destination. A correspondence analysis shows that residents have an overall positive attitude on the development of cruise tourism with respect to social, cultural and economic impacts. Nevertheless, they also feel that cruise activity has a negative impact, especially on the environment. Heterogeneity in occupation is explicitly taken into account. These findings provide directions for local policy‐makers. Copyright © 2012 John Wiley & Sons, Ltd.     

Determinants of spatial knowledge spillovers in Italian provinces

Statistical evidence suggests that the relevance of knowledge spillovers has increased over time. In this paper we focus on regional knowledge spillovers and adopt a new econometric transformation that allows inference on potential inter-regional knowledge spillovers, accounting for spatial interdependencies.Determinants of inter-regional knowledge spillovers are explained with a sample of 103 Italian provinces. We find that a region’s absorptive capacity, measured by local R&D expenditure and social capital, implies a reduction of outward knowledge spillovers.Identification is based on the use of Two Stages Least Squares and Fixed Effects estimates.     

Optimal education and pensions in an endogenous growth model

In OLG economies with life-cycle saving and exogenous growth, competitive equilibria in general fail to achieve optimality because individuals accumulate amounts of physical capital that differ from the one that maximizes welfare along a balanced growth path (the Golden Rule). With human capital, a second potential source of departure from optimality arises, related to education decisions. We propose to recover the Golden Rule of physical and also human capital accumulation. We characterize the optimal policy to decentralize the Golden Rule balanced growth path when there are no constraints for individuals to finance their education investments, and show that it involves education taxes. Also, when the government subsidizes the repayment of education loans, optimal pensions are positive.