Which Null Hypothesis Do Overidentification Restrictions Actually Test?.

In this note I investigate which alternatives are detected by over-identifying restrictions tests, when we test the null hypothesis that all excluded instruments are exogenous. A reformulated null hypothesis will result in a consistent test.

Results of the measurement of atmospheric ozone and hydrocarbons in Baden-Wurttemburg

Data are presented on the diurnal variations of the levels of ozone, ethylene, ethane, and acetylene. The measurement procedures used are described. Variations in monthly ozone levels are given, and measurements from different stations are compared. Data on the total monthly concentrations of NO and NO2 are compared with similar data for ozone. Problems in determining interrelationships among the concentrations of the various substances are discussed

Which null hypothesis do overidentification restrictions actually test?

In this note I investigate which alternatives are detected by over-identifying restrictions tests, when we test the null hypothesis that all excluded instruments are exogenous. A reformulated null hypothesis will result in a consistent test.IV estimation

The Impact of Policies on Poverty Dynamics.

Abstract In this paper we model employment and poverty states as a discrete first-order Markov process, taking into account the endogeneity of schooling and of the initial states. Using this model, we asses the impact of different policies on the poverty dynamics by ex-post microsimulation. Each policy evaluated in this paper can be considered an exemplar of one of the competing paradigms guiding social policy: the traditional welfare state, the active welfare state and the knowledge-based society.Poverty dynamics; Unemployment; Markov models;

Price convergence in the European Union and in the New Member States

This paper examines price dispersion in the European Union (EU15) and in three New Member States (Poland, Hungary and the Czech Republic) between 1995 and 2006. The research is motivated by the fact that the price convergence problem is at the top of the public agenda in many New Member States (NMS). The analysis utilizes both disaggregate and aggregate price data, including the prices of 157 products and two indices constructed using two different weighting procedures. For each category of goods the price dispersion is lower in EU15 than EU15 plus 3 NMS. Sigma convergence measured as a decline in the standard deviation over time is rejected. Unit root tests reject the validity of the Law of One Price (LOOP) for most of the estimations of indices but confirm the LOOP for individual goods. The half-lives are shorter for NMS than for the EU15.price convergence, international price dispersion, law of one price

Analysis of Technical and Policy Changes for Belgian Dairy Farms Using an Estimated Augmented SGM Cost Function

This paper provides some evidence on the evolution of marginal and average costs of dairy farms in Belgium between 1990 and 2007. It investigates the effect of the 2003 Mid-Term Review by adding time trends and linear splines to an augmented multi-input multi-output symmetric generalized McFadden cost function and estimating it using a panel of Belgian dairy farms. Existence of size, scale and scope economies in the dairy sub-sector is also examined. This exercise increases our understanding of dairy farm responses to reforms and helps envision the possible effects of ending the milk quota system as it is now planned for 2015.Livestock Production/Industries,

Sen's capabiliteiten methode.

In dit artikel wordt een overzicht gegeven van de recente ontwikkelingen binnen het kader van Sen's capabiliteitentheorie. Sen biedt een perspectief op welzijn, geconceptualiseerd als het hebben van keuzes en mogelijkheden, dat noch inkomen, noch levensstandaard centraal stelt. Deze laatste worden binnen Sen's perspectief immers als louter instrumenteel beschouwd voor het bereiken van die mogelijkheden. In dit artikel exploreren we de theoretische mogelijkheden en beperkingen van deze aanpak, alsook haar praktische toepasbaarheid.