8,876 research outputs found
Intercept and Recall: Examining Avidity Carryover in On-Site Collected Travel Data
This study examines the proper estimation of trip demand and economic benefits for visitors to recreation sites when past-season trip information is elicited from travelers intercepted on-site. We show that the proper weighting of past season counts is different from the standard on-site correction appropriate for current-season counts. We find that for our sample of lake visitors relatively stronger preference or âavidityâ for the interview site carries over across seasons. We further show that using the correct weighting of past trip counts is critical in deriving meaningful estimates of travel demand and economic benefits.On-site Sampling; Recreation Demand Systems; Poisson-Lognormal Distribution; Simulated Maximum Likelihood
Doubly Robust Inference when Combining Probability and Non-probability Samples with High-dimensional Data
Non-probability samples become increasingly popular in survey statistics but
may suffer from selection biases that limit the generalizability of results to
the target population. We consider integrating a non-probability sample with a
probability sample which provides high-dimensional representative covariate
information of the target population. We propose a two-step approach for
variable selection and finite population inference. In the first step, we use
penalized estimating equations with folded-concave penalties to select
important variables for the sampling score of selection into the
non-probability sample and the outcome model. We show that the penalized
estimating equation approach enjoys the selection consistency property for
general probability samples. The major technical hurdle is due to the possible
dependence of the sample under the finite population framework. To overcome
this challenge, we construct martingales which enable us to apply Bernstein
concentration inequality for martingales. In the second step, we focus on a
doubly robust estimator of the finite population mean and re-estimate the
nuisance model parameters by minimizing the asymptotic squared bias of the
doubly robust estimator. This estimating strategy mitigates the possible
first-step selection error and renders the doubly robust estimator root-n
consistent if either the sampling probability or the outcome model is correctly
specified
Jump-diffusion model of exchange rate dynamics : estimation via indirect inference
This paper investigates asymmetric effects of monetary policy over the business cycle. A two-state Markov Switching Model is employed to model both recessions and expansions. For the United States and Germany, strong evidence is found that monetary policy is more effective in a recession than during a boom. Also some evidence is found for asymmetry in the United Kingdom and Belgium. In the Netherlands, monetary policy is not very effective in either regime.
Adaptive Threshold Sampling and Estimation
Sampling is a fundamental problem in both computer science and statistics. A
number of issues arise when designing a method based on sampling. These include
statistical considerations such as constructing a good sampling design and
ensuring there are good, tractable estimators for the quantities of interest as
well as computational considerations such as designing fast algorithms for
streaming data and ensuring the sample fits within memory constraints.
Unfortunately, existing sampling methods are only able to address all of these
issues in limited scenarios.
We develop a framework that can be used to address these issues in a broad
range of scenarios. In particular, it addresses the problem of drawing and
using samples under some memory budget constraint. This problem can be
challenging since the memory budget forces samples to be drawn
non-independently and consequently, makes computation of resulting estimators
difficult.
At the core of the framework is the notion of a data adaptive thresholding
scheme where the threshold effectively allows one to treat the non-independent
sample as if it were drawn independently. We provide sufficient conditions for
a thresholding scheme to allow this and provide ways to build and compose such
schemes.
Furthermore, we provide fast algorithms to efficiently sample under these
thresholding schemes
Pairwise likelihood estimation for multivariate mixed Poisson models generated by Gamma intensities
Estimating the parameters of multivariate mixed Poisson models is an important problem in image processing applications, especially for active imaging or astronomy. The classical maximum likelihood approach cannot be used for these models since the corresponding masses cannot be expressed in a simple closed form. This paper studies a maximum pairwise likelihood approach to estimate the parameters of multivariate mixed Poisson models when the mixing distribution is a multivariate Gamma distribution. The consistency and asymptotic normality of this estimator are derived. Simulations conducted on synthetic data illustrate these results and show that the proposed estimator outperforms classical estimators based on the method of moments. An application to change detection in low-flux images is also investigated
Bayesian Inference under Cluster Sampling with Probability Proportional to Size
Cluster sampling is common in survey practice, and the corresponding
inference has been predominantly design-based. We develop a Bayesian framework
for cluster sampling and account for the design effect in the outcome modeling.
We consider a two-stage cluster sampling design where the clusters are first
selected with probability proportional to cluster size, and then units are
randomly sampled inside selected clusters. Challenges arise when the sizes of
nonsampled cluster are unknown. We propose nonparametric and parametric
Bayesian approaches for predicting the unknown cluster sizes, with this
inference performed simultaneously with the model for survey outcome.
Simulation studies show that the integrated Bayesian approach outperforms
classical methods with efficiency gains. We use Stan for computing and apply
the proposal to the Fragile Families and Child Wellbeing study as an
illustration of complex survey inference in health surveys
Statistical properties and economic implications of Jump-Diffusion Processes with Shot-Noise effects
This paper analyzes the Shot-Noise Jump-Diffusion model of Altmann, Schmidt and Stute (2008), which
introduces a new situation where the effects of the arrival of rare, shocking information to the financial
markets may fade away in the long run. We analyze several economic implications of the model,
providing an analytical expression for the process distribution. We also prove that certain specifications
of this model can provide negative serial persistence. Additionally, we find that the degree of serial
autocorrelation is related to the arrival and magnitude of abnormal information. Finally, a GMM
framework is proposed to estimate the model parameters
Statistical Properties and Economic Implications of Jump-Diffusion Processes with Shot-Noise Effects
This paper analyzes the Shot-Noise Jump-Diffusion model of Altmann, Schmidt and Stute (2008), which introduces a new situation where the effects of the arrival of rare, shocking information to the financial markets may fade away in the long run. We analyze several economic implications of the model, providing an analytical expression for the process distribution. We also prove that certain specifications of this model can provide negative serial persistence. Additionally, we find that the degree of serial autocorrelation is related to the arrival and magnitude of abnormal information. Finally, a GMM framework is proposed to estimate the model parameters.Filtered Poisson Process, Characteristic Function, Generalized Method of Moments
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