8,733 research outputs found
Dynamic binary outcome models with maximal heterogeneity
Most econometric schemes to allow for heterogeneity in micro behaviour have two
drawbacks: they do not fit the data and they rule out interesting economic models. In this paper
we consider the time homogeneous first order Markov (HFOM) model that allows for maximal
heterogeneity. That is, the modelling of the heterogeneity does not impose anything on the data
(except the HFOM assumption for each agent) and it allows for any theory model (that gives a
HFOM process for an individual observable variable). `Maximal' means that the joint
distribution of initial values and the transition probabilities is unrestricted.
We establish necessary and sufficient conditions for the point identification of our
heterogeneity structure and show how it depends on the length of the panel. A feasible ML
estimation procedure is developed. Tests for a variety of subsidiary hypotheses such as the
assumption that marginal dynamic effects are homogeneous are developed.
We apply our techniques to a long panel of Danish workers who are very homogeneous
in terms of observables. We show that individual unemployment dynamics are very
heterogeneous, even for such a homogeneous group. We also show that the impact of cyclical
variables on individual unemployment probabilities differs widely across workers. Some
workers have unemployment dynamics that are independent of the cycle whereas others are
highly sensitive to macro shocks
Nonparametric methods for the characteristic model
Characteristics models have been found to be useful in many areas of
economics. However, their empirical implementation tends to rely heavily
on functional form assumptions. In this paper we develop a revealed
preference-based nonparametric approach to characteristics models. We
derive the minimal necessary and sufficient empirical conditions under
which data on the market behaviour of individual, heterogeneous, pricetaking
consumers are nonparametrically consistent with the consumer
characteristics model. Where these conditions hold, we show how information
may be recovered on individual consumer’s marginal valuations
of product attributes. In some cases marginal valuations are point identified
and in other cases we can only recover bounds. Where the conditions
fail we highlight the role which the introduction of unobserved product
attributes can play in rationalising the data. We implement these ideas
using consumer panel data on the Danish milk market
Evaluation of Selected Chemical Processes for Production of Low-cost Silicon, Phase 3
Refinements of the design of the 50 MT/year Experimental Process System Development Unit were made and competitive bids were received from mechanical, electrical, and structural contractors. Bids on most of the equipment were received and cataloged. Emergency procedures were defined to counter a variety of contingencies disclosed in operations and safety reviews. Experimental work with an electrolytic cell for zinc chloride disclosed no significant increase in power efficiency by steps taken to increase electrolyte circulation. On the basis of materials compatibility and permeability tests, 310 stainless steel was chosen for the shell of the fluidized-bed reactor and SiC-coated graphite for the liner
The identification of a mixture of first order binary Markov Chains
Let S be the number of components in a finite discrete mixing distribution. We prove that the number of waves of panel being greater than or equal to 2S is a sufficient condition for global identification of a dynamic binary choice model in which all the parameters are heterogeneous. This model results in a mixture of S binary first order Markov ChainsDiscrete choice, Markov processes, Global identification
HABITS AND HETEROGENEITY IN DEMANDS: A PANEL DATA ANALYSIS
We examine demand behaviour for intertemporal dependencies, using Spanishpanel data. We present evidence that there is both state dependence and correlatedheterogeneity in demand behaviour. Our specific findings are that food outside thehome, alcohol and tobacco are habit forming whereas clothing and small durablesexhibit durability. We conclude that demand analyses using cross-section data thatignore these effects may be seriously biased. On the other hand, the degree ofintertemporal dependence is not sufficiently strong to make composite `consumption'significantly habit forming, as has been suggested in some recent analyses.Habits, State dependence, correlated heterogeneity.
Failures of weak approximation in families
Given a family of varieties over a number field , we
determine conditions under which there is a Brauer-Manin obstruction to weak
approximation for of the fibres which are everywhere locally soluble.Comment: 44 pages; there is a new application to integral points (Theorem 1.4)
and Cor 1.5 recovers a well-known result concerning the Hasse principl
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