Agglomeration in an innovative and differentiated industry with heterogeneous knowledge spillovers

This paper introduces an agent-based simulation model to study the technological development, the economic performance of firms and the evolution of agglomerations in a differentiated industry. The analysis is based on the interaction and behavior of firms, which might share knowledge but at the same time are competitors on the goods markets. Firms do not only compete with quantities they can also introduce process and product innovations. The level of knowledge of a firm describes the capabilities to perform innovations. Knowledge can be accumulated by investing in R&D and by knowledge spillover, which depend on geographical and technological proximity. Simulation runs show that there is an incentive to agglomerate in young industries and that geographical proximity enhances innovation, especially the number of product innovations.      

Evidence on corruption as an incentive for foreign direct investment

This paper assesses the relationship between corruption and inward foreign direct investment (FDI). Previous research has presumed that corruption directly enters the cost function of multinationals, suggesting a negative relationship between corruption and FDI. For a sample of 73 developed and less developed countries and the time period 1995–1999, we find a clear positive relationship between corruption and FDI. Corruption is thus a stimulus for FDI.     

Foreign Competition and Wage Inequality

The author argues that increased foreign competition can affect technical choice and skill differentials even when actual imports do not rise significantly. A model is presented of general oligopolistic equilibrium (GOLE) in which a reduction in import barriers (whether technological or policy–imposed) encourages more strategic investment by incumbent firms. The predictions accord with many of the stylized facts: higher skill premia; higher ratios of skilled to unskilled workers employed in all sectors and throughout the economy; little change in import volumes or prices; and rapid technological progress with rather little change in total factor productivity.     

Human Capital and Growth Cycles

This paper studies the dynamic interaction between human capital accumulation and economic growth. Capital market imperfections and an indivisibility in human capital investment prevent poor agents from accumulating skills, the acquisition of which positively affects technological progress. More productive technologies in turn require more sophisticated qualification and involve higher training costs. The equilibrium dynamics can be characterized by the joint evolution of productivity growth, the schooling costs, and the income distribution. Under our assumptions, individual incomes follow a non-linear Markov chain. This non-linearity generates endogenous fluctuations of schooling activities and the rate at which productivity improvements occur. We thank an anonymous referee for many helpful suggestions. Support from the German Research Foundation (DFG) under grant KA1519/2-2 is gratefully acknowledged.     

“Itô's Lemma” and the Bellman Equation for Poisson Processes: An Applied View

Using the Hamilton-Jacobi-Bellman equation, we derive both a Keynes-Ramsey rule and a closed form solution for an optimal consumption-investment problem with labor income. The utility function is unbounded and uncertainty stems from a Poisson process. Our results can be derived because of the proofs presented in the accompanying paper by Sennewald (2006). Additional examples are given which highlight the correct use of the Hamilton-Jacobi-Bellman equation and the change-of-variables formula (sometimes referred to as ``Itô's Lemma'') under Poisson uncertainty.     

International Trade and the Environment: Theoretical and Policy Linkages

I review and extend three approaches to trade and environmental policies: competitive general equilibrium, oligopoly and monopolistic competition. The first two have surprisingly similar implications: deviations from first-best rules are justified only by constraints on policy choice (which motivates what I call a “single dividend” approach to environmental policy), and taxes and emissions standards differ in ways which reflect the Le Chatelier principle. I also show how environmental taxes may lead to a catastrophic relocation of industry in the presence of agglomeration effects, although not necessarily if there is a continuum of industries which differ in pollution intensity. *An earlier version was presented as an invited plenary lecture to the European Association for Environmental and Resource Economics Conference, Oslo, 1999.     

Robust political economy

This paper introduces the idea of “robust political economy.” In the context of political economic systems, “robustness” refers to a political economic arrangement's ability to produce social welfare-enhancing outcomes in the face of deviations from ideal assumptions about individuals' motivations and information. Since standard assumptions about complete and perfect information, instantaneous market adjustment, perfect agent rationality, political actor benevolence, etc., rarely, if ever actually hold, a realistic picture and accurate assessment of the desirability of alternative political economic systems requires an analysis of alternative systems' robustness. The Mises-Hayek critique of socialism forms the foundation for investigations of robustness that relax ideal informational assumptions. The Buchanan-Tullock public choice approach complements this foundation in forming the basis for investigations of robustness that relax ideal motivational assumptions. JEL Code B53, P16, P26     

Wage and Mobility Effects of Trade and Migration on the Austrian Labour Market

This study analyses the effect of trade and migration on wages and labour marketmobility. We estimate wage growth equations and a multinomial logit mobilityequation on an individual data set ranging from 1991 to 1994. We find substantialdifferences in the reactions of white and blue-collar workers wages and mobilityto trade and migration. In Austria exports have a positive and imports a negativeimpact on wage growth only for blue-collar workers. Migrants also reduce onlyblue-collar workers wage growth. Our results indicate that higher imports and aninflow of migrants reduce sectoral mobility of all types workers. The risk of beingout of work by contrast is increased by migration and imports only for blue-collarworkers, but reduced by exports for all types of workers. In general our results suggestenlargement of the EU would have only small effects on the Austrian labour market.     

Trees and decisions

Summary. The traditional model of sequential decision making, for instance, in extensive form games, is a tree. Most texts define a tree as a connected directed graph without loops and a distinguished node, called the root. But an abstract graph is not a domain for decision theory. Decision theory perceives of acts as functions from states to consequences. Sequential decisions, accordingly, get conceptualized by mappings from sets of states to sets of consequences. Thus, the question arises whether a natural definition of a tree can be given, where nodes are sets of states. We show that, indeed, trees can be defined as specific collections of sets. Without loss of generality the elements of these sets can be interpreted as representing plays. Therefore, the elements can serve as states and consequences at the same time.Received: 23 January 2003, Revised: 2 November 2003, JEL Classification Numbers: C72, D70. Correspondence to: Klaus RitzbergerWe are grateful to Larry Blume, Ariel Rubinstein, Jörgen Weibull, an anonymous referee, and seminar participants at the universities of Vienna, Salamanca, and Heidelberg for helpful comments. Financial support from the Austrian Science Fund (FWF) under project P15281 is also gratefully acknowledged.