In linear-quadratic control (LQC) problems with singular control cost matrix and/or singular transition matrix, we derive a reduction of the dimension of the Riccati matrix, simplifying iteration and solution. Employing a novel transformation, we show that, under a certain rank condition, the...

Economic theories of managing renewable resources, such as fisheries and forestry, traditionally assume that individual harvesters are perfectly rational and thus able to compute the harvesting strategy that maximizes their discounted profits. The current paper presents an alternative approach...

Democracies delegate substantial decision power to politicians. Using a model in which an incumbent can design, examine and implement public policies, we show that examination takes place in spite of, rather than thanks to, elections. Elections are needed as a carrot and a stick to motivate...

Long run developments such as income growth and urban sprawl lead one to expect a continuous decline of thecontribution of non-motorised transport modes to the performance of transport systems. In terms of the totalnumber of trips, non-motorised transport modes have retained high shares,...

International and interregional trade and transport are on the rise and hence, there is a clear needfor reliable estimates of transport flows. However, the available databases and estimation methodsare not yet satisfactory for analytical and predictive purposes.In this paper we explore the use...

This paper proposes a new approach to identify the wage effects of training.The idea is to narrow down the comparison group by only taking into consideration theworkers who wanted to participate in training but did not do so because of some randomevent. The point estimate of the return to...

We show that the Anderson-Rubin (AR) statistic is the sum of two independent piv-otal statistics. One statistic is a score statistic that tests location and the other statistictests misspecification. The chi-squared distribution of the location statistic has a degreesof freedom parameter that is...

Approximation formulae are developed for the bias of ordinary andgeneralized Least Squares Dummy Variable (LSDV) estimators in dynamicpanel data models. Results from Kiviet (1995, 1999) are extended tohigher-order dynamic panel data models with general covariancestructure. The focus is on...

This paper studies the relationship between three key elements of the marketing mix, namely, price, product, and promotion, in a model where a seller employs informative advertising to launch a new product. We propose a fairly general advertising technology for the study of three promotional...

The advantages and disadvantages of genetic modification of organisms in agriculture are reviewed. These relate to the environment, human health, socio-economic effects, population growth, and differential consequences for developed and developing countries. An overall evaluation requires that...