Labor-Market Heterogeneity, Aggregation, and the Lucas Critique

This paper assesses biases in policy predictions due to the lack of invariance of "structural" parameters in representative-agent models. We simulate data under various fiscal policy regimes from a heterogeneous-agents economy with incomplete asset markets and indivisible labor supply. Imperfect aggregation manifests itself through preference shocks in the estimated representative-agent model. Preference and technology parameter estimates are not invariant with respect to policy changes. As a result, the bias in the representative-agent model's policy predictions is large compared to the length of predictive intervals that reflect parameter uncertainty.Aggregation; Fiscal Policy; Heterogeneous Agents Economy; Lucas Critique; Representative Agent Models.

Valuing indigenous biodiversity in the freshwater environment

Biosecurity incursion response decisions require timely, high quality information involving science and economics. The value of the impact on indigenous biodiversity is a key aspect of the economics typically involving cost-benefit analysis. The hypothetical incursion of Biosecurity New Zealand’s top priority weed hydrilla (Hydrilla verticillata) in a typical New Zealand lake (Lake Rotoroa otherwise known as Hamilton Lake) elicits dollar values of impacts on indigenous biodiversity in a freshwater environment. Using the stated preference tool, Choice Modelling, the experimental design was maximised for efficiency of Willingness to Pay (WTP) estimation. The survey method of community meetings of four population samples at varying distances to the incursion site is a cross between a mail survey and an individual interview survey. Results show an efficient design with minimal sample size and biodiversity attributes that have values statistically different from zero but not statistically different between locations.Non-market valuation, biosecurity, biodiversity, Community/Rural/Urban Development, Crop Production/Industries, Environmental Economics and Policy, Land Economics/Use,

Estimating Mixed Logit Recreation Demand Models With Large Choice Sets

Discrete choice models are widely used in studies of recreation demand. They have proven valuable when modeling situations where decision makers face large choice sets and site substitution is important. However, when the choice set faced by the individual becomes very large (on the order of hundreds or thousands of alternatives), computational limitations make estimation with the full choice set intractable. Sampling of alternatives in a conditional logit framework is an effective method to limit computational burdens while still producing consistent estimates. This method is allowed by the existence of the independence of irrelevant alternatives (IIA) assumption. More advanced mixed logit models account for unobserved preference heterogeneity and overcome the behavioral limitations of the IIA assumption, however in doing so, prohibit sampling of alternatives. A method is developed where a latent class (finite mixture) model is estimated via the expectations-maximization algorithm and in doing so, allows consistent sampling of alternatives in a mixed logit model. The method is tested and applied to a recreational demand Wisconsin fishing survey.Sampling of alternatives, discrete choice, mixed logit, conditional logit, recreational demand, Wisconsin, fishing, microeconometrics, Environmental Economics and Policy, Research Methods/ Statistical Methods,

Labor-Market Heterogeneity, Aggregation, and the Policy-(In)variance of DSGE Model Parameters

Data from a heterogeneous-agents economy with incomplete asset markets and indivisible labor supply are simulated under various fiscal policy regimes and an approximating representative-agent model is estimated. Preference and technology parameter estimates of the representative-agent model are not invariant to policy changes and the bias in the representative-agent model’s policy predictions is large compared to predictive intervals that reflect parameter uncertainty. Since it is not always feasible to account for heterogeneity explicitly, it is important to recognize the possibility that the parameters of a highly aggregated model may not be invariant with respect to policy changes.Aggregation, DSGE Models, Fiscal Policy, Heterogeneous-Agents Economy, Policy Predictions, Representative-Agent Models

Improving revealed preference bounds on demand responses

There are three key dimensions by which revealed preference bounds on consumer demand responses can be improved. The first relates to the improvements that arise from using expansion paths for given relative prices, E-bounds. The second concerns the addition of new price information. Thirdly, there are improvements due to assuming separability. Our previous research has examined the first two cases. In this article, we show how to impose separability assumptions within a fully nonparametric analysis and distinguish between weak and homothetic separability. We also apply these ideas to the analysis of demand responses using United Kingdom household level data

Efficient Estimation of Linear Asset Pricing Models with Moving-Average Errors

This paper explores in depth the nature of the conditional moment restrictions implied by log-linear intertemporal capital asset pricing models (ICAPMs) and shows that the generalized instrumental variables (GMM) estimators of these models (as typically implemented in practice) are inefficient. The moment conditions in the presence of temporally aggregated consumption are derived for two log-linear ICAPMs. The first is a continuous time model in which agents maximize expected utility. In the context of this model, we show that there are important asymmetries between the implied moment conditions for infinitely and finitely-lived securities. The second model assumes that agents maximize non-expected utility, and leads to a very similar econometric relation for the return on the wealth portfolio. Then we describe the efficiency bound (greatest lower bound for the asymptotic variances) of the CNN estimators of the preference parameters in these models. In addition, we calculate the efficient CNN estimators that attain this bound. Finally, we assess the gains in precision from using this optimal CNN estimator relative to the commonly used inefficient CMN estimators.

Evaluating Alternative Representations of the Choice Sets in Models of Labour Supply

During the last two decades, the discrete-choice modelling of labour supply decisions has become increasingly popular, starting with Aaberge et al. (1995) and van Soest (1995). Within the literature adopting this approach there are however two potentially important issues that are worthwhile analyzing in their implications and that up to know have not been given the attention that they might deserve. A first issue concerns the procedure by which the discrete alternative are chosen. For example Van Soest (1995) chooses (non probabilistically) a set of fixed points identical for every individual. This is by far the most widely adopted method. By contrast, Aaberge et al. (1995) adopt a sampling procedure and also assume that the choice set may differ across the households. A second issue concerns the availability of the alternatives. Most authors assume all the values of hours-of-work within some range [0, H] are equally available. At the other extreme, some authors assume only two or three alternatives (e.g. non-participation, part-time and full-time) are available for everyone. Aaberge et al. (1995) assume instead that not all the hour opportunities are equally available to everyone; they specify a probability density function of opportunities for each individual and the discrete choice set used in the estimation is built by sampling from that individual-specific density function. In this paper we explore by simulation the implications of - the procedure used to build the choice set (fixed alternatives vs sampled alternatives) - accounting vs not accounting for a different availability of alternatives. The way the choice set is represented seems to have little impact on the fitting of observed values, but a more significant and important impact on the prediction of policy effects.Microeconometric Models, Discrete Choice, Choice Set, Labour Supply, Tax Reforms.

Equity and Aggregation in Environmental Valuation

Environmental valuation studies aim at the assessment of the social benefits or the social costs caused by some change in environmental quality (in the broadest sense). The most popular field of application of environmental valuation studies is project appraisal where the benefits arising from some environmental project (measured in terms of people's willingness to pay for that project) are assessed and confronted with the costs of the project or with the benefits from some alternative project if a choice has to be made between different projects. A closer look at the results of empirical valuation studies shows that in many surveys a negative correlation between the number auf household members and the willingness to pay (WTP) stated by a household for a project can be observed. These results are rather puzzling because in larger households more people are going to benefit from an environmental improvement than in small households. A plausible explanation for these results is that household budgets are tighter for large households than for smaller households with the same household income. Therefore, large households must state a smaller WTP for a project than smaller households with the same income and the same preferences. This might have consequences for the allocation of public funds in all cases where the realization of a specific environmental project depends on the absolute value of the aggregate social benefits it generates. In order to calculate the social benefits typically the WTPs of the different households affected by that project are added up. In this aggregation process the members of larger households have a lower weight and, therefore, their WTP has a smaller impact on the decision if a certain project is realized or not. The reason for this violation of the principle of horizontal equity is that for the computation of the social benefits not individual but household WTPs are aggregated. In this paper we suggest to use household equivalence scales for the evaluation of WTP data in order to reduce this discrimination of the members of large families. We demonstrate the effects of equivalence scales on the results of environmental valuation surveys using an empirical study carried out in Eastern Germany.contingent valuation; Environmental Valuation; Equity