فصلنامه مدلسازی اقتصادی
سال دهم شماره 1 (پیاپی 33، بهار 1395)

The aim of this paper is to study the relationship between the lobby and bribeand behavior analysis and firms selection. So, to test this theory and determine the relation between lobbying and bribing, the data of more than twenty six thousand firms from 45 countries reported by The World Bank Enterprise Survey (2002-2005) are used. Because of the interaction between lobby and bribe, and, that lobby is a zero-one dummy variable, a combination of simultaneous equations estimation method and Probit regressions are used. As a main result, it is shown that, although lobby substitutes the bribery, but this relationship is not symmetric. 3 groups of variables including countrywide characteristics, industrial and firm-level factors affect the choice between lobbying and bribing. Lobby decreases bribery, but the substitution is not complete so that half of the lobbying firms still use bribery as a mean to cover the risk of lobbying failure. Higher lobbying winning chance or firm’s affordability to accept the risk of failure through for example external financing decreases the need to bribe to insure the risk of lobbying failure and, thus, make the substitution stronger.

The main aim of this study is to model and analyze the challenge of inheritance allocation remained by a passed-away couple based on the inheritors strategies and objectives by using Game Theory approach. So, by the help of Graph model to analyze the challenges between the inheritors of a passed-away couple based on the laws and regulations in Islamic Republic o Iran. This model contains two kinds of players selected through 64 abstract constructions of the strategies by applying some limitations and analyzed 8 possible cases and finally, 2 cases predicted as more likely. The results represent that this competition has two equilibriums. That is, if the players stand in thie situations, they have no desire to exit. By the coalition of the players, the results will be more appropriate to get more. The findings of the modeling is completely consistent with real results of the challenges.

Economic approach to the marriage represent that optimal conditions in family formation are realized whenever the man loves equally himself and his wife and so the household resources will be equally distributed. Accordingly, the purpose of this paper is to consider the credibility of this idea and to find empirical evidence. By using a sample including of 415 married men residing in Tehran, empirical evidence suggest that higher income of women tends to convey marriage to optimality but the age and education of women go in opposite direction. In addition, the number of children and the degree of resemblance of couple's tastes will have positive impact on reaching to optimal marriage. At last, marriage will be close to optimality, if the men’s education is higher than the women’s occurred in lower ages and the number of children and the degree of understanding between the couples is more. The most important implication of this paper is that the similar characteristics of men and women are not necessarily a favorite situation in marriage but some discrepancies seem to be better.

In this paper, based on the importance of Inter-fuel substitution, the researcher try to study the changes in Inter-fuel substitution in OECD and then to answer the question that "whether it has any effect on the fluctuation of Iran's petroleum exports in this market or not?" By using Linear Dynamic Logit model based on the equations of fuel and SURE to investigate inter-fuel substitution through four fuels including oil, gas, coal and electricity represent that the electricity and gas is the most intensive in short and long-term alternative to oil. The estimation of this system as simultaneous to MSI model for Iran's oil exports in OECD market indicate that these substitutions affect the fluctuations of Iranian petroleum exports.

This paper is to evaluate the effect of price changes in 8 main commodity groups on rural households during 2001-2012. To estimate subsistence level, rural household's data issued by Iranian Statistics Center is used. In addition, by the the results of linear expenditure system, the price and income elasticities is calculated along with the compensation and equivalent variations of Iranian Rural households. The results represent that subsistence level for Rural households is 40637 thousand Rials in the year 2012. Furthermore, the compensation and equivalent variations calculated by of commodity groups indicate the increase of prices in each commodity group of subsistence level will decrease rural households welfare.

The purpose of this paper is to examine the cyclical consequences of Efficiency Wage theory when changing the workers efforts based on Dynamic Real Business Cycle model by using the data collected during 1966-2014. The equations are estimated through oleic approach (1999) as a space-state model in MATLAB context. The results represent that the increase of efforts variability to efficiency wage consideration causes the variables like production, consumption, labor and employment rate react less to technology shock. According to this model, higher level of workers efforts will lead to the increase of employment rate.

Health is one the main indicators of development and investment affecting directly on welfare and economic growth.The most important factors affecting economic growth are the labor, physical capital and human capital.Health is an indicator of human capital leading to an increase in labor productivity and thus economic growth.So, health expenditure is introduced an investment in human capital. One of the main challenges in health sector is to identify the factors determining the amount of resources devoted by a country to health care. The misery index is one of these factors.The aim of this study is to evaluate the role of misery index on health expenditure in Iran during 1971 to 2011.The results represent that there is a significant negative relationship between misery index and health expenditures.According to estimations, the government size estimated coefficient, urbanization rate and per capita income have a significant positive effect and education estimated coefficients and income inequality have a significant negative impact on health expenditure in Iran.