This study uses "Multiple Indicators-Multiple Causes" (MIMIC) APPROACH to model the causal relations between main variables, which determine the underground economy in Iran. We Basically, it examines the relationship between underground and official GDP in Iran, using annual time-series data for Iran during 1965-2005. Accordingly, it is found that the estimated size of the underground economy varies from 6.24 percent in 1965 to 26.15 percent of the formal economy in 2005, while the related minimum and maximum values were 5.50 and 27.76 percent of the economy in 1967 and 2001, respectively. The underground economy is significantly and positively affected by variables such as unemployment and inflation, but negatively by the degree of economic openness.

Underground economy has various names in economics literature like, black economy, unregulated economy, and unreported economy and so on. Since there is no exact definition for the Underground economy, in this study we try to measure it indirectly by using the observable variables and build a model to explain it. Then we try to estimate the model by Maximum likelihood and Instrumental Variable methods.The aim of this paper is to estimate the size of the Underground economy in Iran by using the unobservable variable model (Multiple indicator and multiple causes). Our estimates show that the share of the Underground economy in Iran was about 17.21 percent of the Gross Domestic Product (GDP) during 1350-1386. Our result also indicates that the tax Gap was about 22 percent of the total tax revenue for the above-mentioned period. For a number of reasons, which will be discussed later in the main text, the size of the Underground economy and tax gap is increasing for the foreseeable future in the economy of Iran.

Education is a continually developing activity, it shapes the way an individual develops their attitudes, thoughts and behavior. Education is not just about being literate but it is an overall development of the person in every aspect of their lives. A society's educational system can be greatly linked to its culture as the culture that one is in have an affect on the type of curriculum the institutions will develop in order to cater to every individual of that particular culture. Education moulds and shapes a society and it is influenced by the culture of the particular country or society. The educational system acts as a point of reference for the society's needs and demands. The principles that dominate this article is culture and education are interrelated and interconnected. Every educational paradigm is influenced by the culture of the society in which it operates. This essay underlines the extensive connection between culture and education. As a result, the goal of this essay is to depict these features from a Philosophical-Psychological APPROACH.

Amyotrophic lateral sclerosis (ALS) misdiagnosis has many broad implications for the patient and the neurologist. Potentially curative treatments exist for certain ALS MIMIC syndromes, but delay in starting these therapies may have an unfavorable effect on outcome. Hence, it is important to exclude similar conditions. In this review, we discuss some of the important MIMICs of ALS.

The underground economy is one of the problems of developing oil economies such as Iran. It is argued that the underground economy can hinder financial development, and from the reciprocal view, financial development can reduce the size of the underground economy. Accordingly, the present study examines the causality between financial development (bank-oriented and stock-oriented) and the volume of underground economy in the Iran's economy by the Hsiao causality method during the period of 1350-1396. In this study, the MIMIC APPROACH was used to calculate the underground economy index in Iran. Based on the results, in the Iran economy before the oil shock of 1352 and also the period of revolution and war (1356-1368) has had a low level and decreasing trend in terms of underground economy. But for the rest of the years, the trend has been roughly incremental. According to the Hsiao causality test, the underground economy is not the cause of the bank based financial development-and stock based financial development; on the contrary, bank based financial development-and stock based financial development are the cause of the underground economy. This means that with financial development, part of the underground economy can be controlled in the Iran economy.

Artifacts are ubiquitous and influential in our world, but their nature and existence are controversial. Several theories have been proposed to explain the ontology of artifacts. Drawing on Popper's theory of three worlds, this paper suggests a metaphysics for artifacts along the line of a critical rationalist (CR) APPROACH. This theory distinguishes between three realms of reality: the physical world (World 1), the mental world (World 2), and the world of objective knowledge (World 3). The paper argues that artifacts have different ontological components that correspond to these three realms, and that each component is real and causal. The paper shows how this perspective can account for the intentional and functional aspects of artifacts, as well as their dependence on plans that influence different realms of reality. The paper explains how this pluralistic ontology, compared to the rival theories, enables one to explain the relevant ontological problems of artifacts. The paper also explores how this proposal can lead to a research program encompassing a broader range of technologies, such as social artifacts. In sum, the paper suggests that Popper's three worlds theory provides a rich and comprehensive framework for understanding the metaphysics of artifacts.