We investigate conditions sufficient for identification of average treatment effects using instrumental variables. First we show that the existence of valid instruments is not sufficient to identify any meaningful average treatment effect. We then establish that the combination of an instrument and a condition on the relation between the instrument and the participation status is sufficient for identification of a local average treatment effect for those who can be induced to change their participation status by changing the value of the instrument. Finally we derive the probability limit of the standard IV estimator under these conditions. It is seen to be a weighted average of local average treatment effects.

Evolution and Rationality Some Recent Game-Theoretic Results. Identification and Estimation of Local Average Treatment Effects

This paper investigates the effect of idiosyncratic ( firm-le vel) policy distortions on aggregate outcomes. Exploiting harmonized firm - level data for a number of countries, we show that there is substantial and systematic cross - country variation in the within-industry covariance between size and productivity. We develop a model in which heterogeneous firms face adjustment frictions (overhead labor and quasi-fixed capital) and distortions. The model can be readily calibrated so that variations in the distribution of distortions allow matching the observed cross-country moments. We show that the differences in the distortions that account for the size-productivity covariance imply substantial differences in aggregate performance. (JEL D24, L25, O47) A vast theoretical and empirical literature has been devoted to identify the sources of the large and persistent differences in productivity across countries. At the same time, a parallel strand of research has emerged over the past decade suggesting large and persistent heterogeneity in firm-level productivity, even in narrowly defined industries, in a variety of countries (e.g., Bartelsman, Haltiwanger, and Scarpetta 2004).

https://www.nber.org/system/files/working_papers/w15490/w15490.pdf

Cross-Country Differences in Productivity: The Role of Allocation and Selection

The Communication program emphasizes theory, research, and application to examine the ways humans communicate, verbally and non-verbally, across a variety of levels and contexts. This is particularly important as communication shapes our ideas and values, gives rise to our politics, consumption and socialization, and helps to define our identities and realities. Its power and potential is inestimable. From the briefest of text messages to the grandest of public declarations, we indeed live within communication and invite you to join us in appreciating its increasing importance in contemporary society. From Twitter and reality television to family relationships and workplace dynamics, communication is about understanding ourselves, our media, our relationships, our culture and how these things connect.

의사 간호사 communication

Recent sovereign defaults in emerging countries are accompanied by interest rate spikes and deep recessions. This paper develops a small open economy model to study default risk and its interaction with output, consumption, and foreign debt. Default probabilities and interest rates depend on incentives for repayment. Default occurs in equilibrium because asset markets are incomplete. The model predicts that default incentives and interest rates are
higher in recessions, as observed in the data. The reason is that in a recession, a risk averse borrower finds it more costly to repay non-contingent debt and is more likely to default. In a quantitative exercise the model matches various features of the business cycle in Argentina
such as: high volatility of interest rates, higher volatility of consumption relative to output, a negative correlation of interest rates and output and a negative correlation of the trade balance and output. The model can also predict the recent default episode in Argentina.

/pdf/default-risk-and-income-fluctuations-in-emerging-economies-3uwetnmpe6.pdf

Default Risk and Income Fluctuations in Emerging Economies

In this paper, I construct an equilibrium for markets with frictions, which is competitive in the sense that all agents are price takers and maximize utility subject to a set of market parameters. I show that the equilibrium allocation is socially optimal. I also show how the competitive search equilibrium can be achieved if employers with vacancies can advertise publicly the wages they pay.

Competitive Search Equilibrium

. This paper studies ethnic discrimination in Germany's labour market with a correspondence test. We send two similar applications to each of 528 advertisements for student internships, one with a Turkish-sounding and one with a German-sounding name. A German name raises the average probability of a callback by about 14%. Differential treatment is particularly strong and significant in smaller firms at which the applicant with the German name receives 24% more callbacks. Discrimination disappears when we restrict our sample to applications including reference letters which contain favourable information about the candidate's personality. We interpret this finding as evidence for statistical discrimination.

/pdf/ethnic-discrimination-in-germany-s-labour-market-a-field-5cxmtgt6xp.pdf

Ethnic Discrimination in Germany's Labour Market: A Field Experiment

The introduction of firm size into labor search models raises the question how wages are set when average and marginal product differ. We develop and analyze an alternative to the existing bargaining framework: Firms compete for labor by publicly posting long–term contracts. In such a competitive search setting, firms achieve faster growth not only by posting more vacancies, but also by offering higher lifetime wages that attract more workers which allows to fill vacancies with higher probability, consistent with empirical regularities. The model also captures several other observations about firm size, job flows, and pay. In contrast to bargaining models, efficiency obtains on all margins of job creation and destruction, both with idiosyncratic and aggregate shocks. The planner solution allows a tractable characterization which is useful for computational applications.

/pdf/efficient-firm-dynamics-in-a-frictional-labor-market-184s000luz.pdf

Efficient Firm Dynamics in a Frictional Labor Market

Within a macroeconomic disequilibrium model it turns out that stationary and simple adaptive policies are not capable of stabilizing efficient steady states and lead to periodic or irregular fluctuations for large sets of policy parameters. The application of recent control methods for chaotic dynamical systems shows that the government can, in principle, stabilize an unstable Walrasian equilibrium in a short time by varying income tax rates or government expenditures. Different stabilizing policies are analyzed and compared with regard to their efficiency.

/pdf/stabilizing-chaos-in-a-dynamic-macroeconomic-model-3defjbt8op.pdf

Stabilizing chaos in a dynamic macroeconomic model

http://directory.umm.ac.id/Data%20Elmu/jurnal/J-a/Journal%20Of%20Economic%20Dynamics%20And%20Control/Vol24.Issue5-7.Jul2000/1247.pdf

Differential savings, factor shares, and endogenous growth cycles

The paper analyzes how the removal of barriers to entry in banking affect loan competition, bank stability and economic welfare. We consider a model of spatial loan competition where a market that is served by less efficient banks is opened to entry by banks that are more efficient in screening borrowers. It is shown that there is typically too little entry and that market shares of entrant banks are too small relative to their socially optimal level. This is because efficient banks internalize only the private but not the public benefits of their better credit assessments. Only when bank failure is very likely or very costly, socially harmful entry can occur.

Leo Kaas

Papers

Ethnic Discrimination in Germany's Labour Market: A Field Experiment

Efficient Firm Dynamics in a Frictional Labor Market

Stabilizing chaos in a dynamic macroeconomic model

Differential savings, factor shares, and endogenous growth cycles

Financial market integration and loan competition : when is entry deregulation socially beneficial?