The impact of climate change on China's agriculture

This article examines how expected changes in climate are likely to affect agriculture in China. The effects of temperature and precipitation on net crop revenues are analyzed using cross-sectional data consisting of both rainfed and irrigated farms. Based on survey data from 8,405 households across 28 provinces, the results suggest that global warming is likely to be harmful to rainfed farms but beneficial to irrigated farms. The net impacts will be only mildly harmful at first, but the damages will grow over time. The impacts also vary by region. Farms in the Southeast will only be mildly affected but farms in the Northeast and Northwest will bear the largest damages. However, the study does not capture the indirect effects on farms of possible changes in water flow, which may be important in China.     

Super‐replication in fully incomplete markets

In this work, we introduce the notion of fully incomplete markets. We prove that for these markets, the super‐replication price coincides with the model‐free super‐replication price. Namely, the knowledge of the model does not reduce the super‐replication price. We provide two families of fully incomplete models: stochastic volatility models and rough volatility models. Moreover, we give several computational examples. Our approach is purely probabilistic.     

Bundling agricultural technologies to adapt to climate change

Farmers can respond to climate change by modifying their technologies or management practices, or both. In this paper, we examine the choice of crop, irrigation, and cover as a bundled decision by a farmer. Using discrete choice analysis and a cross section of farms from Israel, we test whether these decisions are sensitive to climate and find that they are. In the case of Israel, the farmers completely substitute capital for climate. Simulating increase in temperature suggests that warming would lead Israeli farmers to shift mainly to orchards under cover and irrigation. But it is likely that bundling adaptations will provide flexibility and sustainability for future farmers in many locations under climate change conditions.     

Choosing the two finalists

This paper studies a decision maker who for each choice set selects a subset of (at most) two alternatives. We axiomatize three types of procedures: (i) The top two: the decision maker has in mind an ordering and chooses the two maximal alternatives. (ii) The two extremes: the decision maker has in mind an ordering and chooses the maximal and the minimal alternatives. (iii) The top and the top: the decision maker has in mind two orderings and he chooses the maximal element from each.     

How to Count Patents and Value Intellectual Property: The Uses of Patent Renewal and Application Data

Patent counts are very imperfect measures of innovative output. This paper discusses how additional data—the number of years a patent is renewed and the number of countries in which protection for the same invention is sought—can be used to improve on counts in studies that require a measure of the extent of innovation. Simple weighting schemes are proposed, which may remove half of the noise in patent counts as a measure of innovative output. We describe models of the patent application and renewal processes whose parameter estimates can be used to assess the value of the proprietary rights created by the patent laws. We illustrate their use with estimates of how the value of patent protection would vary under alternative legal rules and renewal fees and with estimates of the international flows of returns from the patent system. Recent progress in the development of databases has increased the potential for this type of analysis.     

Welfare consequences of water supply alternatives in rural Tunisia

Many economic studies have addressed the issue of inefficiency of public water supply in rural areas and the potential for improved service by private companies. Many of these analyses focused on identifying either willingness to pay or comparing average service costs and prices paid by customers. This paper performs a welfare analysis of two water supply systems—public and self owned—in rural Tunisia. The paper calculates consumer and producer surplus and compares the performance of the two systems from a social point of view. Results suggest that both systems are inefficient, mainly because of a production level that is low compared with production capacity.     

The Relative Efficiency and Implementation Costs of Alternative Methods for Pricing Irrigation Water

A useful means for achieving efficient allocation of irrigationwater is to put the right price tag on it. This article discussessome of the more pervasive pricing methods and compares theirefficiency performance, paying special attention to the impactof the cost of implementing each method on its efficiency. Thearticle uses an empirical example to demonstrate numericallythe relative efficiency of the different pricing methods andthe important role of implementation costs. The volumetric,output, input, tiered, and two-part tariff methods all can achieveefficiency, although the type of efficiency varies from onemethod to another. These methods also differ in the amount andtype of information, and the administrative cost, needed intheir implementation. The example indicates that water pricingmethods are most pronounced through their effect on the croppingpattern—more so than through their effect on water demandfor a given crop. Implementation costs have a large effect onwater tariffs and on welfare and hence should have an importantrole in determining the desirable method to use in any givenwater situation.     

The Israeli XBRL Adoption Experience

eXtensible Business Reporting Language (XBRL) is a language for the electronic communication of business and financial data which is revolutionizing business reporting around the world. It is a tool to bridge potential language barriers and unify financial reporting. This has appeal to foreign investors, among others, who can rely on information in XBRL‐tagged financial reports to make investment decisions without having to translate financial statements from local language. In 2008, Israel required most public companies to adopt International Financial Reporting Standards (IFRS) for financial reporting and to use XBRL‐tagged reporting format, as part of an aggressive effort to make its capital markets more transparent and attractive for foreign investors. In this paper, we study all Israeli public companies and analyze the accuracy and reliability of their XBRL‐tagged financial statements that are available on MAGNA, the Israel Securities Authority's electronic system. We describe the process by which the XBRL‐based data were collected and reported. We document, categorize, and analyze deficiencies in the XBRL‐tagged filings, and inconsistencies between them and the Hebrew‐based annual reports. We observe pervasive data entry errors resulting in inaccurate XBRL‐generated financial reports, which went undetected for over one year. Further, first year XBRL reporting (in conjunction with IFRS adoption) did not increase foreign investment in the Israeli capital markets. This analysis allows us to better understand the benefits and challenges of the adoption of XBRL.     

ECONOMIC FREEDOM AND STATE BOND RATINGS

Are state bond ratings, ceteris paribus, related to economic freedom? We test for the relationship between economic freedom and an aggregate index comprised of ratings by Standard & Poor, Moody's, and Fitch. We also test for a relationship between economic freedom and the ratings by these three agencies individually. With a sample covering all 50 states for the period 1995–2008, the evidence strongly indicates that state bond ratings are positively and significantly related to overall economic freedom as well as three sub‐categories of economic freedom. Our results show that the quantitative impact of economic freedom on bond ratings is comparable to the effect of state real income and the unemployment rate. (JEL E43, H71)