Despite being a mainstay of modern economic theory, the simple concept of arbitrage is sorely misused. In this paper we overview such instances, and offer an alternative definition. Most applications of arbitrage use it as a general equilibrating tendency irrespective of whether the outcome is...

We show that both real indeterminacy and asset price bubble may appear in an infinite-horizon exchange economy with infinitely lived agents and an imperfect financial market. We clarify how the asset structure and heterogeneity (in terms of preferences and endowments) affect the existence and...

We build a dynamic general equilibrium model with heterogeneous producers and financial frictions (collateral constraints and incompleteness). First, we provide a characterization to check whether a sequence is an equilibrium or not. Second, we study the effects of financial imperfections on...

In a simple infinite-horizon exchange economy with a single consumption good and a financial asset, real indeterminacy and asset price bubble may arise. We show how heterogeneity (in terms of preferences, endowments) and short-sale constraints affect the emergence and the dynamics of asset price...

The paper introduces dividend taxation and productive government spending in an infinite-horizon general equilibrium model with heterogeneous agents and financial market imperfections. We point out that imposing a dividend tax and using the revenue from this tax to finance productive government...

We present some theoretical frameworks used in macroeconomics, mainly economic growth. Our goal is not to provide a unified model but rather to present simplified versions of models in the classic academic articles to help students familiarize with theoretical models used in macroeconomics and...

Demichelis and Polemarchalis (2007) highlighted the role played by the frequency of trade on the degree of indeterminacy of equilibrium in economies of overlapping generations. Assuming that time has a finite starting point and extends into the infinite future, they prove that the degree of...

We study the causes of inequality in human capital accumulation across ethnic and religious groups. An overlapping generations model in which agents decide how much time to invest in human capital versus ethnic capital shows that the demand for human capital is affected positively by parental...

Economics, and other fields of social science are often criticized as unscientific for their apparent failures to formulate universal laws governing human societies. Whether economics is truly a science is one of the oldest questions. This paper attempts to create such universal laws, and...

The arrow-of-time phenomena are everywhere in the physical world, biological systems, and human society. Despite its great importance in physics, the second law of thermodynamics can only successfully explain small percentages of these arrow-of-time phenomena in the physical world, and generally...