The distributional impact of large dams: Evidence from cropland productivity in Africa

We examine the distributional impact of large dams on cropland productivity in Africa. As our unit of analysis we use a hydrology based spatial breakdown of the continent that allows one to exactly define regions in terms of their upstream/downstream relationship at a highly disaggregated level. We then use satellite data to derive measures of cropland productivity within these areas. Our econometric analysis shows that while regions downstream benefit from large dams, no beneficial effects accrue to cropland within the vicinity. Moreover, we find that the productivity enhancing impact of upstream dams is dependent on the local climate. Overall our results suggest that upstream dams have quantitatively on average provided up to 12% of the minimum daily per capita amount of kilocalorie needs in downstream communities and increased agricultural production by 1%.     

The inflation and inflation uncertainty relationship for Turkey: a dynamic framework

This article assesses the interaction between inflation and inflation uncertainty in a dynamic framework for Turkey by using monthly data for the time period 1984–2009. The bulk of previous studies investigating the link between inflation and inflation uncertainty employ Autoregressive Conditional Heteroskedasticity (ARCH)-type models, which consider inflation uncertainty as a predetermined function of innovations to inflation specification. The stochastic volatility in mean (SVM) models that we use allow for gathering innovations to inflation uncertainty and assess the effect of inflation volatility shocks on inflation over time. When we assess the interaction between inflation and its volatility, the empirical findings indicate that response of inflation to inflation volatility is positive and statistically significant. However, the response of inflation volatility to inflation is negative but not statistically significant.     

Are Preferential Trade Agreements with Non-trade Objectives a Stumbling Block for Multilateral Liberalization?

In many preferential trade agreements (PTAs), countries exchange not only reductions in trade barriers but also cooperation in non-trade issues such as labour and environmental standards, intellectual property, etc. We provide a model of PTAs motivated by cooperation in non-trade issues and analyse its implications for global free trade and welfare. We find that such PTAs increase the cost of multilateral tariff reductions and thus cause a stumbling block to global free trade. This occurs because multilateral tariff reductions decrease the threat that can be used in PTAs and thus the surplus that can be extracted from them. By explicitly modelling the interaction between preferential and multilateral negotiations, we derive a testable prediction and provide novel econometric evidence that supports the model's key prediction. The welfare analysis shows that the current World Trade Organization rules allowing this type of PTAs may be optimal for economically large countries, thus the model can predict the rules we observe. We also analyse alternative rules that constitute a Pareto improvement.     

The winner-loser anomaly: recent evidence from Greece

This article finds evidence of significant reversals in returns over the medium term in Greek stocks. In contrast with previous research, return reversals are more pronounced for past winners, suggesting that the market overreacts to a greater extent to good news. These contrarian returns are particularly elevated when portfolios are formed using quartiles and during tranquil and bull markets. The optimum contrarian strategy involves skipping the first 6 months of the holding period and implementing the contrarian strategy for a period of 18 months, as returns exhibit continuation followed by reversal. The profitability of the contrarian investment strategy is robust to adjustments for risk and seasonalities. It is the tranquil times and not the crisis/volatile times that generates a significant and profitable contrarian strategy. The recent credit crisis and resulting stock market falls, resulted in extreme movements in some Greek stocks and testing of the contrarian strategy problematic, especially when portfolios are decile ordered. Our findings also highlight the importance of survivorship bias and also suggest that contrarian strategies that just use market beta may be ill-equipped to take into consider extreme market movements, illiquidity and short-sales constraints.     

Maximum efforts in contests with asymmetric valuations

Efforts may be reduced when players with different valuations participate in a contest. This paper considers the problem of designing a contest to elicit maximum aggregate effort from players with asymmetric valuations. Optimal designs for different classes of contest technologies are computed and characterized. A value weighted contest is optimal in the concave case. In the unconstrained case, the optimal contest is equivalent to a first price all-pay auction with a reserve price. The optimal design discounts the effort of the high valuation player in order to induce him to compete vigorously.     

Functions of innovation systems as a framework to understand sustainable technological change: Empirical evidence for earlier claims

Understanding the emergence of innovation systems is recently put central in research analysing the process of technological change. Especially the key activities that are important for the build up of an innovation system receive much attention. These are labelled ‘functions of innovation systems’. This paper builds on five empirical studies, related to renewable energy technologies, to test whether the functions of innovation systems framework is a valid framework to analyse processes of technological change. We test the claim that a specific set of functions is suitable. We also test the claim made in previous publications that the interactions between system functions accelerate innovation system emergence and growth. Both claims are confirmed.     

A review and validation of overall survival extrapolation in health technology assessments of cancer immunotherapy by the National Institute for Health and Care Excellence: how did the initial best estimate compare to trial data subsequently made available?

Background: Validation of overall survival (OS) extrapolations of immune-checkpoint inhibitors (ICIs) during the National Institute for Health and Care Excellence (NICE) Single Technology Assessment (STA) process is limited due to data still maturing at the time of submission. Inaccurate extrapolation may lead to inappropriate decision-making. The availability of more mature trial data facilitates a retrospective analysis of the plausibility and validity of initial extrapolations. This study compares these extrapolations to subsequently available longer-term data.

Methods: A systematic search of completed NICE appraisals of ICIs from March 2000 to December 2017 was performed. A targeted search was also undertaken to procure published OS data from the pivotal clinical trials for each identified STA made available post-submission to NICE. Initial Kaplan-Meier curves and associated extrapolations from NICE documentation were extracted to compare the accuracy of OS projections versus the most mature data.

Results: The review identified 11 STAs, of which 10 provided OS data upon submission to NICE. The extrapolations undertaken considered parametric or piecewise survival models. Additional data cut-offs provided a mean of 18 months of OS beyond the end of the original data. Initial extrapolations typically under-estimated OS from the most mature data cut-off by 0.4–2.7%, depending on the choice of assessment method and use of the manufacturer- or ERG-preferred extrapolation.

Conclusion: Long-term extrapolation of OS is required for NICE STAs based on initial immature OS data. The results of this study demonstrate that the initial OS extrapolations employed by manufacturers and ERGs generally predicted OS reasonably well when compared to more mature data (when available), although on average they appeared to underestimate OS. This review and validation shows that, while the choice of OS extrapolation is uncertain, the methods adopted are generally aligned with later-published follow-up data and appear appropriate for informing HTA decisions.     

Charges in the Industrial Water Sector: Comparison Between Ireland and Spain

The European Treaty supports the application of the polluter pays principle in all environmental policies including the Water Framework Directive. This paper assesses the efficiency of water-charging systems in two European regions. The regions examined are the South west region of Ireland and the Navarre region in Spain which were selected because they are similar in terms of economic indicators but different in terms of water pricing structures. The paper describes the development and application of a simple model to analyse data on water-charging systems from these two regions. We present the results of a detailed scenario-based investigation illustrating the differences between experience, composition and basis, impact and constraints on the application of water charges for both regions. The key findings are that existing water charges do not provide incentives for users to use water efficiently and thereby do not contribute effectively to the environmental objectives of the Water Framework Directive.     

Eurosystem monetary targeting: Lessons from U.S. data

Using a small empirical model of inflation, output, and money estimated on U.S. data, we compare the relative performance of monetary targeting and inflation targeting. The results show monetary targeting to be quite inefficient, yielding both higher inflation and output variability. This is true even with a nonstochastic money demand formulation. Our results are also robust to using a P∗ model of inflation. Therefore, in these popular frameworks, there is no support for the prominent role given to money growth in the Eurosystem's monetary policy strategy.     

AGRICULTURAL POLICY AT THE CROSSROADS—AGAIN

American agriculture is suffering from severe structural adjustments and from its worst financial depression since landmark price and income policies were legislated more than half a century ago. As much as one-third of the $220 billion in agricultural debt is now delinquent, nonaccrual, or subject to renegotiation. Land values have fallen precipitously in the past few years. Farm foreclosures are near 1930 Depression levels. The congressional debate over programs that could determine the course of U.S. agriculture for the remainder of the century began in the summer of 1985.