Steganographer Identification

Conventional steganalysis detects the presence of steganography within single objects. In the real-world, we may face a complex scenario that one or some of multiple users called actors are guilty of using steganography, which is typically defined as the Steganographer Identification Problem (SIP). One might use the conventional steganalysis algorithms to separate stego objects from cover objects and then identify the guilty actors. However, the guilty actors may be lost due to a number of false alarms. To deal with the SIP, most of the state-of-the-arts use unsupervised learning based approaches. In their solutions, each actor holds multiple digital objects, from which a set of feature vectors can be extracted. The well-defined distances between these feature sets are determined to measure the similarity between the corresponding actors. By applying clustering or outlier detection, the most suspicious actor(s) will be judged as the steganographer(s). Though the SIP needs further study, the existing works have good ability to identify the steganographer(s) when non-adaptive steganographic embedding was applied. In this chapter, we will present foundational concepts and review advanced methodologies in SIP. This chapter is self-contained and intended as a tutorial introducing the SIP in the context of media steganography.Comment: A tutorial with 30 page

MODELING TECHNICAL TRADE BARRIERS UNDER UNCERTAINTY

As traditional forms of agricultural protection continue to decline, agricultural interests will likely seek alternative protection in the form of technical barriers. A flexible framework for theoretically and empirically analyzing technical barriers under various sources of uncertainty is derived. Attention is focused on uncertainty arising from the variation in the product attribute levels, a source not yet considered by the literature. Ex ante and ex post densities of domestic and international quantities and prices as well as the densities of their respective extreme-order statistics are derived. An example is presented to illustrate the application of the developed framework.International Relations/Trade,

Rating Crop Insurance Policies with Efficient Nonparametric Estimators that Admit Mixed Data Types

The identification of improved methods for characterizing crop yield densities has experienced a recent surge in activity due in part to the central role played by crop insurance in the Agricultural Risk Protection Act of 2000 (estimates of yield densities are required for the determination of insurance premium rates). Nonparametric kernel methods have been successfully used to model yield densities; however, traditional kernel methods do not handle the presence of categorical data in a satisfactory manner and have therefore tended to be applied on a county-by-county basis. By utilizing recently developed kernel methods that admit mixed data types, we are able to model the yield density jointly across counties, leading to substantial finite sample efficiency gains. Findings show that when we allow insurance companies to strategically reinsure with the government based on this novel approach they accrue significant rents.discrete data, insurance rating, kernel estimation, yield distributions, Risk and Uncertainty,

Transferring Water in the American West: 1987-2005

Rising urban and environmental demand for water has created growing pressure to re-allocate water from traditional agricultural uses. Water markets are powerful institutions for facilitating this re-allocation, yet the evolution of water markets has been more complicated than those for other resources. In this paper, we set the context for water marketing with an overview of western water law that highlights unique aspects of water law that affect how or whether a water market can develop. Second, we present new, comprehensive data on the extent, nature, and timing of water transfers across 12 western states from 1987-2005. We describe the methodology and decision rules used to collect water transfer information. Third, we identify water market trends and movements to provide a greater understanding of the institutional structure and the mechanisms by which water is transferred in the American West

ON CHOOSING A BASE COVERAGE LEVEL FOR MULTIPLE PERIL CROP INSURANCE CONTRACTS

For multiple peril crop insurance, the U.S. Department of Agriculture'Â’s Risk Management Agency estimates the premium rate for a base coverage level and then uses multiplicative adjustment factors to recover rates at other coverage levels. Given this methodology, accurate estimation of the base coverage level from 65% to 50%. The purpose of this analysis was to provide some insight into whether such a change should or should not be carried out. Not surprisingly, our findings indicate that the higher coverage level should be maintained as the base.Risk and Uncertainty,

WEATHER-BASED ADVERSE SELECTION AND THE U.S. CROP INSURANCE PROGRAM: THE PRIVATE INSURANCE COMPANY PERSPECTIVE

Surprisingly, investigations of adverse selection have focused only on farmers. Conversely, this article investigates if insurance companies, not farmers, can generate excess rents from adverse selection activities. Currently political forces fashioning crop insurance as the cornerstone of U.S. agricultural policy make our analysis particularly topical. Focusing on El Nino/La Nina and winter wheat in Texas, we simulate out-of-sample reinsurance decisions during the 1978 through 1997 crop years while reflecting the realities imposed by the risk-sharing arrangement between the insurance companies and the federal government. The simulations indicate that economically and statistically significant excess rents may be garnered by insurance companies through weather-based adverse selection.Risk and Uncertainty,

Did the unfounded claim that Turkey was about to join the EU swing the referendum?

Even in 2016 - before Turkey's latest turn towards authoritarianism - the chances of the country joining the EU before 2030 were remote. Yet this did not prevent Vote Leave from claiming towards the end of the referendum campaign that Turkey was poised to join. This unfounded claim, writes James Ker-Lindsay (LSE), played into voters' existing worries about immigration. It may even have swung the result

There is a good case to be made for Cyprus pressing ahead with full recognition of Kosovo’s independence

Cyprus is one of the five EU member states that refuse to recognise the independence of Kosovo from Serbia. James Ker-Lindsay writes that a recent meeting between the Cypriot Foreign Minister and the Prime Minister and Foreign Minister of Kosovo suggests that the country’s stance may be softening over the issue. He notes that although this may seem surprising given Cyprus’s own dispute with the self-declared Turkish Republic of Northern Cyprus, it is in keeping with changing attitudes among other EU member states and a shift in Cypriot foreign policy. He also argues that if a change is to be made, there is a good case for pressing ahead with full recognition