Informational Smallness and the Scope for Limiting Information Rents

For an incomplete-information model of public-good provision with interim participation constraints, we show that e¢ cient outcomes can be approximated, with approximately full surplus extraction, when there are many agents and each agent is informationally small. The result holds even if agents' payoffs cannot be unambiguously inferred from their beliefs, i.e., even if the so-called BDP property ("Beliefs Determine Preferences") of Neeman (2004) does not hold. The contrary result of Neeman (2004) rests on an implicit uniformity requirement that is incompatible with the notion that agents are informationally small because there are many other agents who have information about them.surplus extraction, mechanism design, BDP, informational smallness, correlated information

Concept and Structure of Tolerance (Experience of Theoretical Research)

Norms and values in societies are different in civilizational, historical, and ethnical aspect because they were formed according to the specific historical needs of each society. They contain the requirements for both intolerant and tolerant attitude towards ‘others’. The modern concept which social scientists use to try to grasp the sense of “peaceful coexistence in a multicultural society” is the concept of ‘tolerance’. Social science borrowed the concept of tolerance from medicine where tolerance is defined as a neutral or insignificant reaction of a living being to biologically active substances and objects that enter it. In social science itself, tolerance appears as a compromise (conflict-free) behavior in a multicultural society. According to the principles of organization, tolerance is divided into radical (fundamental non-violence) and moderate (civil society). Based on behavior, tolerance represents four levels: 1) unconscious tolerance (symbiosis); 2) conscious (educated) tolerance (indifference, conformism, understanding, consent); 3) self-serving (interaction, cooperation, solidarity); 4) actual (emotional) tolerance (affection, reciprocity, infatuation, love). In total, we get 22 (4 conscious + 3 self-serving + 4 actual) × 2 (radical and moderate) types of tolerance, plus unconscious tolerance/symbiosis. The problem of tolerance is the problem of the correlation of good and harm arising from compromise (conflict-free) behavior in a multicultural society. Therefore, tolerance is an individual measure of good/harm arising from compromise (conflict-free) behavior in a multicultural society. Values can be normative (individual measure of good/harm corresponding to their social measure) and non-normative (individual measure of good/harm not corresponding to their social measure). The absence of a definition of tolerance in modern legislation indicates the normative nature of this value. Consequently, tolerance is a non-normative value of compromise (conflict-free) behavior in a multicultural society. Aim: theoretical study and definition of the concept and structure of tolerance. Keywords: tolerance, value, norm, structure of toleranc

Selling \u27Money\u27 on EBay: a Field Study of Surplus Division

We study the division of trade surplus in a natural field experiment on German eBay. Acting as a seller, we offer Amazon gift cards with face values of up to 500 Euro. A random selection of buyers, the subjects of our experiment, make price offers according to the rules of eBay. Using a novel decomposition method, we infer the offered shares of trade surplus from the data and find that the average share proposed to the seller amounts to about $30 \%$. Additionally, we document: (i) insignificant effects of stake size; (ii) poor use of strategically relevant public information; and (iii) differences between East and West German subjects

Essays in mechanism design

The thesis studies some theoretical and applied problems in the mechanism design. In the first part we study how a group of agents could organize themselves to collect resources to introduce a common governance system which will enforce their trade agreements (contracts) with each other. Governance systems dealing with those issues usually have some costs of functioning (e.g., wages of enforcers, costs of design of codes and statutes, etc.) and they are also characterized by non-rivalry (i.e. an additional member does not reduce its availability to all others). Thus, studying their feasibility is equivalent to the problem of provision of (excludable) public goods. The first chapter analyzes this problem in the following setup: A large population of agents heterogeneous in strength endowments could match one-shot to trade with each other and there exists a status-quo asymmetric punishment system that imposes a punishment for cheating on weak agents but not on strong ones. There is an opportunity to build a punishment institution that will impose punishment for cheating independently of agents’ identities; however, it requires a collective investment into its capacity up-front. The main results of the analysis are the following: (i) the rate of cheating is always positive in contracts subject to asymmetric punishment and it is zero in contracts subject to impartial punishment, i.e. if the latter were not costly, it would always be socially beneficial to have only a symmetric governance system; (ii) sometimes strong agents receive rents under the asymmetric system, but sometimes it is the weak who benefit from it; (iii) there exists an equilibrium of the contribution game where all agents, independently of their strength, pay to the fixed cost of the symmetric system provided it excludes non-contributors from enforcement of their contracts with contributors, i.e. with the threat of exclusion of non-payers it is always possible to collect resources to cover costs of the efficient contract enforcement institution. In the second part of my thesis, which constitutes a joint paper with Martin Hellwig, we work out some details on whether under correlated information agents’ beliefs about the state of nature, which a third party may observe, are also fully informative about agents’ information on which their beliefs are conditioned. This property of agents’ beliefs plays a crucial role in the models of surplus extraction where agents' payoff parameters are privately known. Some recent literature (Heifetz and Neeman, Econometrica, 2006) demonstrated that when one goes beyond a standard model of information where agents derive their beliefs from a common prior given their payoff parameter and allows for a rich set of agents' beliefs, then, under a wide range of circumstances, agents’ beliefs could not reveal unequivocally their information, i.e., one could not learn agents' payoffs from their beliefs. Hence mechanisms exploiting uniqueness of payoffs to beliefs are not available anymore. We demonstrate the opposite result -- provided that agents’ beliefs are conditional distributions given their information (derived from common or private priors) and provided a mild restriction on the dimensionality of information variables is verified (specifically agents' own information should be of a lower dimension than dimensionality of their uncertainty about which they form beliefs). Then, in a wide range of circumstances, agents' information could be recovered from their beliefs. The result hinges upon Whitney Embedding Theorem and our treating of beliefs as being endogenously derived from agents' observations. In the third part of the thesis we deal with the following issue: In the existing mechanism design literature, different types of an agent, i.e., different states in which he has different sets of information, are usually treated as "redundant" if they have the same belief hierarchies about others' payoffs (i.e., beliefs about others' payoffs, beliefs about others' beliefs about everyone else’s payoff, etc.). Consequently most of the results in the existing literature have been shown for subsets of type spaces up to redundancy. Here we demonstrate that this approach is not always correct. If we model explicitly agents' redundant characteristics, there may exist social choice functions which are not implementable when those characteristics are not considered but which are implementable within a richer model taking into account redundant information. The reason for this is that treating some types as redundant is done by marginalizing beliefs about a richer set of uncertainty into beliefs about something of a lower dimension. This causes loss of information about correlations in a richer environment. These correlations are sometimes valuable for implementation as the mechanism designer could condition those agents' allocations

Festival Advertising Phenomenon

Cовременная реклама служит средством увеличения дохода рекламодателя, но в то же время она способна стать самостоятельным объектом восприятия, образцом искусства рекламы, демонстрирующим интересные креативные решения и актуальный смысловой посыл. В статье анализируется феномен фестивальной рекламы, выявляются ее функции и критерии оценки.Modern advertising serves as a means of increasing the advertiser’s revenue. It is also an art and can demonstrate creative solutions and relevant meanings. The article analyzes the phenomenon of festival advertising, identifies its functions and evaluation criteria

Effectiveness of a personalised elimination diet in children with food anaphylaxia

The purpose of the study. Evaluate the effectiveness of a personalised elimination diet by the number of repeated anaphylactic reactions and the need for drug therapy in children with food anaphylaxis.Цель исследования. Оценить эффективность персонифицированной элиминационной диеты на число повторных анафилактических реакций и потребность в медикаментозной терапии у детей с пищевой анафилаксией

Thromboembolic risk factors and predictors of left atrial appendage thrombosis in Far North patients with nonvalvular atrial fibrillation

Aim. To analyze thromboembolic risk factors and identify additional predictors of left atrial appendage (LAA) thrombosis, which are not included in the CHA2DS2VASc scale, in long-term Far North residents with nonvalvular atrial fibrillation (AF).Material and methods. The study included 162 patients (men, 108; women, 54; mean age, 55,3±8,7 years) with non-valvular AF, living in the Far North, and 684 patients (men, 408; women, 276; mean age, 56,9±9,3 years), living in the temperate latitudes, hospitalized for catheter ablation. All patients underwent transthoracic and transesophageal echocardiography. According to transesophageal echocardiography, Far North patients were divided into two groups: group 1 — 21 patients with LAA thrombosis, group 2 — 141 patients without LAA thrombosis.Results. Compared to patients living in the temperate latitudes, Far North patients were younger (p=0,021) and were more likely to have type 2 diabetes (14,2% vs 8,3%, p=0,022), class ³II obesity (29,6% vs 21,1%, p=0,019), persistent AF(47,5% vs 33,2%, p=0,0019), LAA thrombosis (13% vs 6,6%, p=0,006), and severe structural and functional cardiac abnormalities (biatrial and right ventricular enlargement, lower left ventricular ejection fraction). In Far North patients, using logistic regression, independent predictors of LAA thrombosis were identified: an increase in left ventricular mass index (odds ratio (OR), 1,029; 95% confidence interval (CI), 1,011-1,048; p=0,001), persistent AF (OR, 3,521; 95% CI, 1,050-11,800; p=0,041).Conclusion. In Far North patients with nonvalvular AF, scheduled for catheter ablation, compared with patients from temperate latitudes, with a similar profile of cardiovascular diseases at a younger age, type 2 diabetes, grade ³II obesity, persistent AF, and LAA thrombosis were more common. The presence of persistent AF and an increase in left ventricular mass index are independent predictors of LAA thrombosis in Far North patients with nonvalvular AF

Fibrosis biomarkers as predictors of left atrial appendage thrombosis in patients with nonvalvular atrial fibrillation

Aim. To compare clinical, echocardiographic characteristics and blood biomarkers in patients with nonvalvular atrial fibrillation (AF) depending on the presence of left atrial appendage (LAA) thrombus and to identify independent predictors of LAA thrombosis.Material and methods. Patients with nonvalvular AF subjected to transesopha geal echocardiography before catheter ablation were divided into 2 groups comparable by sex and age: group 1 (n=45) — with LAA throm bosis; group 2 (n=97) — without LAA thrombosis. The patients underwent transthoracic and transesophageal echocardiography. In addition, the following blood biomarkers were analyzed: NT-proBNP (pg/ml), GDF-15 (pg/ml), TGF-β1 (pg/ml), PIIINP (ng/ml), high-sensitivity C-reactive protein (hsCRP) (mg/l), cystatin C (mg/l).Results. In group 1, persistent AF, coronary artery disease, heart failure were more often noted. In addition, group 1 patients had higher volume indices of both atria, left ventricular mass index and pulmonary artery systolic pressure, as well as lower left ventricular ejection fraction and blood flow velocity in the LAA. There were no differences in the groups in terms of the mean CHA2DS2VASc score, the proportion of patients taking oral anticoagulants (OAC), and the OAC spectrum. In group 1, higher levels of NT-proBNP (p=0,0001), GDF15 (p=0,0001), PIIINP (p=0,0002) were found with no differences in the levels of TGF-β1, hsCRP and cystatin C. A stepwise logistic regression revealed independent predictors of LAA thrombosis: LA volume index (ml/m2) — odds ratio (OR)=1,084, 95% confidence interval (CI) 1,028-1,143 (p=0,003); GDF15 ≥933 pg/ml — OR=3,054, 95% CI, 1,260-7,403 (p=0,013); PIIINP ≥68 pg/ml — OR=5,865, 95% CI, 2,404-14,308 (p<0,001). There were following model quality parameters: AUC=0,815 (p<0,001), specificity, 74,4%, sensitivity, 72,7%.Conclusion. In patients with nonvalvular atrial fibrillation taking OAC, serum levels of fibrosis biomarkers PIIINP ≥68 pg/mL and GDF-15 ≥933 pg/mL, along with the left atrial volume index, were independent predictors of LAA thrombosis