This paper primarily deals with the merits of the Market economy and its legal infrastructure, i.e. private law. The economic philosophy underpinning economic liberalism is based on the profound insight into the limits of human nature, which makes economic planning almost impossible. This is because social and economic interactions arc infinite and transitory. The legal framework for such interactions is private law, which combines order and freedom, However, the same normative system under which Market economy and private law arc favored can also identity some shortcomings and failures, which have to be dealt with by some policy and regulatory measures. Free operation of Market may fail to achieve justice or efficiency. This failure is manifested in monopolies, asymmetric of information, externalities and national and political interests. Once the failure of Market in these fields is established, the choice of legal and polity responses is the next step. To rectify the above mentioned areas of Market failure we have to either use broad policy instruments such as tax or subsidies or resort to the regulatory laws such as competition law, securities regulation, environmental law, intellectual property laws, exchange control and foreign trade law.

Special mathematical techniques have been developed in order to analyze conflict-competition situations. Game theory provides a formal analytical framework with a set of mathematical tools to study the complex intersections among rational players (Osborne, 2004). Several approaches have been produced to the Portfolio selection problem, which became popular among researchers with the article of Harry M. Markowitz, published in Journal of finance in 1952, which occupies an essential place in the literature. Canonical Coalition Game Theory is among these approaches. In this paper the optimality of a portfolio partnership which will be created by each player’s strategies (stocks) with identical targets but different Beta capabilities will be examined first with a zero-sum game and then with establishing a coalition among different Beta groups (players). The obtained optimal gain will be distributed to each stock using Shapley vector. As a result the performance of the model’s portfolio was positive and better than Market performance which resulted negative return during testing period.

Today the long run and systematic attitude to environmental sustainability, is being the concern of policy makers and planers in world, regional, national and local level in developed countries. Although a lot of environmental challenges can be outlined, but water scarce and air pollution are the most important challenges. Urban development beside the life pattern changes and convert of automobile from one luxury goods to essential goods in families consumption basket, caused improvement of oil products and is the most important source of air pollution in major cities.Automobile industries protection, causes the environmental pollutions to a less important subject. These pollutants include SO2, NOx, CO, CO2 and HC that can an unfavorable effects on health. In developed countries, a lot of policies are used to reducing pollutants. One of the usual policy is focus on producing the high environmental efficiency automobiles.This research uses the information of 19 ordinary cars in domestic Market in 2014 (Iranian calendar 1393 shamsi). Some models is designed and solved for computing the dimensional and total environmental efficiency of cars. The results with application of Data Envelopment Analysis (DEA) model show that MVM110, Pride and ROA have been the inefficient cars in production of CO2, HC and CO respectively. In evaluation of total environmental inefficiency, ROA is the most inefficient and Zantia is the most efficient car in case study.

Both public procurement and competition law represent two of the basic components of Market regulation and affect highly on the efficiency and development of economics. Economics has always played a more significant role in competition law while public procurement regulations and practices are a source of Market failure. By their inflexible price policies, they generate a big negative impact on Market dynamics and impose an efficiency loss on society. The government as the main buyer can cause monopsony and their action in the Market can detract from perfect competition. The public procurement regulation may remove a number of suppliers from public Market. Whilst government may benefit in the short term from cost-saving and low prices, by these reductions of opportunities and imposing prices on suppliers, the long term effects can be destructive and worse Market conditions for fringe buyers—, both in terms of reduced variety and (in the long run) in higher prices. In order to justify the view that public procurement is a source of potential distortion in Market competition, this research has criticized the monopsony of government and its effects on suppliers and other smaller buyers.

In a free Market, spending Market participants in the form of private law institutions (law of contracts, civil liability, property rights) does not necessarily meet the objectives of competition law and will not have full competition. This is particularly due to the specialization of the legal profession and the factors such as Asymmetric information between lawyer and client makes this Market in the event of failure and not satisfy the interests of the consumers of these services. This article is intended to express that in this issue what is the Market sailure and what solutions can be offered. In short, we can say that the liberalization of the Market and removing barriers to competition, must have a minimal supervision in the form of "regulation" exist to ensure quality of the service, In this paper, we express the characteristics of the Market and then look at its failures and a variety of mechanisms to respond to it

In recent decades, identification and analyzing of behaviourial factors affecting investors failure is one of the most important subjects in investment Markets. In this research, identification and analyzing the nature of behaviourial factors that cause investors failing at Iran’ s stock Market is studied. This researchs approach is qualitative and analytical methods is used for. This research from data collection aspect is survey using non-structured interviews and from conclusions usage view is applied. At the framework of this survey, cognitive mapping method is used to map 12 experts of Iran’ s stocks Market perceptions about the causes of investors failure. In analyzing this map, analyzing methods of cognitive maps is used. Finally conclusions showed that 27 factors affecting investors failure based on mostly 70 percent experts agreement. These 27 factors can be divided into two “ Inefficient implementation of effective decision” and “ Ineffective decision making" clusters. Also “ Lack of adequate, effective and efficient knowledge” , “ inefficient and inadequate experience” , and “ inappropriate strategy layout” more than other factors affecting the investment failure agreed upon by the participants in the research.