Mesenteric cyst with milk of calcium

A mesenteric cyst with milk of calcium in an adult patient is presented. Preoperative evaluation included plain film, ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI). To our knowledge, the presence of milk of calcium in a mesenteric cyst has not been previously described.     

Small bowel enema and diagnosis of chronic nonischemic disturbance of superior mesenteric venous blood flow

Chronic nonischemic disturbance of mesenteric venous blood flow is reported in 11 patients with a mean age of 19 years. This entity, rarely discussed n the literature, is different from acute thrombosis and chronic thrombotic forms with portal hypertension or hypercoagulopathy. In eight patients this syndrome was secondary to organic lesions of different origin: mesenteric vein squeezed by fibrous bands or an abnormal jejunal artery (four cases), lymphoma involving the distal superior mesenteric veins (three cases), hemangioma causing microthrombi (one case). In three patients no etiology or predisposing factor was found. All patients presented with rectal hemorrhage. Small bowel enema showed a constant pattern in 11 patients: small nodules, modified by compression or peristalsis, involving the mesenteric border of the jejunoileal segment, and associated with thick, straight but regular folds. Mesenteric varices were suspected and led to angiographic studies which were normal in three cases, confirmed varices in eight cases, and thrombosis in four cases. Laparotomy was normal in three cases and established the etiological diagnosis in eight cases. Varices were shown in six cases. Arteriography and laparotomy were unable to reach a complete diagnosis.     

Peritoneal mesothelioma: Sonographic findings in nine cases

Ultrasonographic findings in nine cases of peritoneal mesothelioma are presented. The most common findings were sheetlike or nodular peritoneal thickening, soft tissue masses, fixation of the intestinal loops, mesenteric thickening, and minimal ascites which was disproportional to the degree of tumor dissemination. The authors found that abdominal sonography, using 3.75–7.5 MHz transducers, is a useful imaging method for diagnosis of peritoneal mesothelioma in high-risk groups.     

Superior mesenteric artery aneurysm in Behçet's disease

Behçet's disease is a multisystem disorder characterized by recurrent orogenital ulcerations and uveitis. Vascular involvement can include both arteries and veins, with a preponderance of venous lesions. Aneurysms of splanchnic arteries due to Behçet' s disease have been rarely reported. We present an unusual case of superior mesenteric artery aneurysm due to Behçet's disease diagnosed by ultrasonography and angiography.     

Intraperitoneal seeding from hepatoma

We report three cases of intraperitoneal seeding from hepatoma. Manifestation of intraperitoneal seeding from hepatoma were intraperitoneal masses (N = 2) and peritoneal thickening (N = 1). Main vascular feeder to intraperitoneal masses was omental branches of the gastroduodenal artery and/or the superior mesenteric artery.     

Stochastic optimization applied to self-financing portfolio: does bequest matter?

The article studies stochastic optimization of an intertemporal consumption model to allocate financial assets between risky and risk-free assets. We use a stochastic optimization technique, in which utility is maximized subject to a self-financing portfolio constraint. The papers in literature have estimated the errors of Euler equations using data from financial markets. It has been shown that it is sufficient to test the first order Euler equation implied by the model. However, they all assume a constant consumption–wealth ratio that constrains the boundary conditions, hence influencing the coefficient of the risk premium. The main contribution of our article is that we drop the assumption of a constant consumption–wealth ratio. We have an analytical solution using a utility maximization model with a stochastic self-financing portfolio. We introduce a terminal condition of wealth with and without bequests. We also simulate the stochastic optimization with a self-financing portfolio, distinguishing risk neutral investors (γ-low) from high risk averse investors (γ-high). We show that the model with bequest has a higher level of wealth and a smoother decline of consumption over time than the model with no bequest at the end of the period. The model with no bequest has the same level of consumption and a sharp fall at the end of the period. Risk averse agents with high return assets have a higher amount of wealth than risk-neutral agents with lower return assets.     

Intertemporal pricing in laboratory posted offer markets with differential information

Summary. This paper analyzes intertemporal seller pricing and buyer purchasing behavior in a laboratory retail market with differential information. A seller posts one price each period that a buyer either accepts or rejects. Trade occurs over a sequence of "market periods" with a random termination date. The buyer and seller are differentially informed: The seller's cost of producing a unit of a fictitious good is known and constant in all periods, but the buyer's value for the good (demand) is a random variable governed by a Markov Process whose structure is common knowledge. At the beginning of each period the unit's value is determined by "nature" and is privately revealed only to the buyer. The market termination rule is a binary random variable. We conduct 32 laboratory experiments designed to study intertemporal pricing by human subjects in the Posted Offer Institution when demand follows a stochastic process. There are four series of experiments: 8 with simulated buyers, 8 with inexperienced subjects, 8 with once experienced subjects, and 8 with twice experienced subjects.     

公共支出转型及其经济发展效应研究

笔者基于政府职能转变视角,考察了公共支出转型中的规模与结构变化,并对其经济发展效应进行了实证分析。研究发现:(1)中国公共支出已经由经济建设型转向公共服务型;(2)公共支出规模与经济增长率和社会不公平指数正相关;(3)经济建设性支出占总支出比重与经济增长率负相关,与社会不公平指数正相关;(4)公共服务性支出占总支出比重与经济增长率正相关,与社会不公平指数负相关。     

Using Angler Characteristics and Attitudinal Data to Identify Environmental Preference Classes: A Latent-Class Model

A latent-class model of environmental preference groups is developed and estimated with only the answers to a set of attitudinal questions. Economists do not typically use this type of data in estimation. Group membership is latent/unobserved. The intent is to identify and characterize heterogeneity in the preferences for environmental amenities in terms of a small number of preference groups. The application is to preferences over the fishing characteristics of Green Bay. Anglers answered a number of attitudinal questions, including the importance of boat fees, species catch rates, and fish consumption advisories on site choice. The results suggest that Green Bay anglers separate into a small number of distinct classes with varying preferences and willingness to pay for a PCB-free Green Bay. The probability that an angler belongs to each class is estimated as function of observable characteristics of the individual. Estimation is with the expectation–maximization (E–M) algorithm, a technique new to environmental economics that can be used to do maximum-likelihood estimation with incomplete information. As explained, a latent-class model estimated with attitudinal data can be melded with a latent-class choice model. Edward Morey and Jennifer Thacher are equal authors and rotate authorship across articles.     

Ownership advantages,home production,foreign production and exports of direct investing firms—Some evidence from austrian firms

This paper formulates a simple model of a monopolistic, horizontally integrated, multinational firm with multiplant economies of scale generated by inputs with public good characteristics. The econometric analysis of the model conducted with a sample of Austrian firms points to a substitutive relationship of foreign production and home production with foreign production significantly lowering exports. The estimation results, however, indicate in accordance with the economic model that multiplant economies of scales significantly lower the magnitude of substitution. Holding exports constant a complementary relationship between home production and foreign production would appear indicating that substitution would be much higher in the absence of multiplant economies of scale.     

Tax reform in a two-class growth model

This paper analyzes the welfare and distributional effects of tax reforms in a two-class model with exogenous labour supply. It extends the empirically calibrated, standard life-cycle model to include both pure life-cycle savers and households with an altruistic bequest motive. The tax reform simulations cover the move from an income to a wage and a consumption tax, respectively. The role of borrowing constraints is studied and a dynamic analysis of tax reforms using a static expectation approach is performed. The simulation results indicate that the two tax reforms have different impacts on the welfare of the two classes: while the pure life-cycle savers are better off with the consumption tax, the altruistically motivated households gain more under a wage tax. The results further show that while the introduction of a consumption tax is distributionally neutral, the move to a wage tax substantially increases income and wealth inequality.     

Path Dependence,Endogenous Innovation,and Growth*

The article presents a model of endogenous innovation and growth, in which technological change is path dependent. The historical pattern of technological development plays a central role in determining the pace of future technological change. Path dependence is explained using a distinction between fundamental and secondary knowledge. The economy moves endogenously between periods of drastic and nondrastic innovation. Technological lock‐in is shown to be a special case of path dependence. The model provides a rationale for cycles in technological leadership. This rationale exists in equilibria with positive levels of fundamental research and in a world with no imitation.     

How transition paths differ: Enterprise performance in Russia and China

We use enterprise survey data to analyse and contrast the determinants of enterprise performance in China and Russia. We find that in China, enterprise growth and efficiency is associated with rapid increases in factor inputs, and with ownership to a lesser extent, but not greatly correlated with industry-specific or institutional factors. However, in Russia, enterprise growth is not associated with improvements in factor quantity (except for labor) or quality. The main determinants of company performance are instead demand and institutional factors at a regional level. The findings are robust across a variety of specifications.     

Economywide impacts of climate change on agriculture in Sub-Saharan Africa

Two possible adaptation scenarios to climate change for Sub-Saharan Africa are analyzed under the SRES B2 scenario. The first scenario doubles the irrigated area in Sub-Saharan Africa by 2050, compared to the baseline, but keeps total crop area constant. The second scenario increases both rainfed and irrigated crop yields by 25% for all Sub-Saharan African countries. The two adaptation scenarios are analyzed with IMPACT, a partial equilibrium agricultural sector model combined with a water simulation module, and with GTAP-W, a general equilibrium model including water resources. The methodology combines the advantages of a partial equilibrium approach, which considers detailed water-agriculture linkages, with a general equilibrium approach, which takes into account linkages between agriculture and nonagricultural sectors and includes a full treatment of factor markets. The efficacy of the two scenarios as adaptation measures to cope with climate change is discussed. Due to the limited initial irrigated area in the region, an increase in agricultural productivity achieves better outcomes than an expansion of irrigated area. Even though Sub-Saharan Africa is not a key contributor to global food production (rainfed, irrigated or total), both scenarios help lower world food prices, stimulating national and international food markets.     

Investigating the distribution of personal income obtained from the recent U.S. data

This study considered the conservation of money in a closed economic system. In such system, the probability distribution of money is exponential, and similar to the Boltzmann-Gibbs function in a closed energy system. The theoretical concept of econophysics is compared here with empirical data. The current work analyzes the recent data with regard to personal income distribution obtained from United States Census Bureau for the years 2006, 2007 and 2008. The data was best fitted with the exponential function, which supports the theoretical assumption for the income of the majority of the population. This study also investigates this distribution for a population with high personal income.     

Profit rate in the US, 1949–2007: a Markov switching assessment

The article investigates the growth in the general profit rate in the US during the 1949–2007 period with a Markov switching model. The evidence is consistent with a long swing with means displaying opposite signs under the two regimes (increasing or declining) and high degree of persistence within each regime. The results for this nonlinear approach reinforce previous empirical evidence that does not provide support for a systematic and declining tendency in profit rate as advanced in the Marxian literature.     

Credit Chains and Mortgage Crises

Here I examine a production economy with a financial sector that contains multiple layers of credit. The latter constitute credit chains that include a simple mortgage market. The focus is on the nature and contagion properties of credit chains in an economy where the financial sector plays a real allocating role, and agents have a serious choice of whether to default on mortgages or not. Multiple equilibria with different rates of default are observed, due to the presence of strategic complementarities. A liquidity crunch is associated with higher rates of default that can trigger a financial crisis as well as constrain the purchase of production factors, leading to reductions in welfare, together with potentially serious effects on real economic activity with the potential of causing deep and widespread recessions.     

Preemptive investment game with alternative projects

This paper investigates a duopoly with two alternative investment projects. We examine a situation in which a firm cannot invest in any project that has been taken by the rival firm. The first mover's advantage in project choice leads to an equilibrium quite different from that in previous studies. Specifically, we show that in equilibrium, the investment time and the option value are between those in a duopoly with one project and a monopoly with one project. Moreover, we show that a high correlation between project values, unlike in a monopoly with two projects, plays a positive role in mitigating preemptive competition. The results complement the literature of real options games and of max-options and entail new empirical implications.     

ON FINANCE AS A THEORY OF TFP,CROSS‐INDUSTRY PRODUCTIVITY DIFFERENCES,AND ECONOMIC RENTS*

We develop a theory of capital‐market imperfections to study how the ability to enforce contracts affects resource allocation across entrepreneurs of different productivities, and across industries with different needs for external financing. The theory implies that countries with a poor ability to enforce contracts are characterized by the use of inefficient technologies, low aggregate TFP, large differences in labor productivity across industries, and large employment shares in industries with low productivity. These implications are supported by the empirical evidence. The theory also suggests that entrepreneurs have a vested interest in maintaining a status quo with low enforcement.