Skip to main content

Estimation and testing of nonproportional Weibull hazard models

Buy Article:

$51.63 plus tax (Refund Policy)

Abstract:

Most applications of the Weibull hazard model specify a common shape parameter. This is a proportional hazard model that imposes a common rate of duration dependence. A wide class of nonproportional Weibull models may be estimated by making the shape parameter a linear function of observable regressors. The log-likelihood function for these models is well behaved. The conditions under which this generalization is useful are essentially the same conditions under which interaction terms are useful in classical regression. Since the nonproportional model nests the proportional model, a formal test for nonproportionality may be conducted by likelihood ratio test. Estimation and testing of nonproportional models is illustrated with data sets for housing sales, out-of-court settlements and oil field exploration. Finally, estimation of a proportional Weibull model after adding temporal interaction terms to the regressors that specify the scale parameter is shown to be a fundamental misspecification. The standard log-likelihood function fails to recognize the stochastic nature of temporal interaction terms and the resulting estimates often fall outside the parameter space of the Weibull.

Keywords: C41; C51; Weibull; duration; hazard; nonproportional

Document Type: Research Article

DOI: http://dx.doi.org/10.1080/00036846.2011.648322

Affiliations: Department of Economics,Florida State University, 253A Bellamy,Tallahassee 32306-2180, USA

Publication date: May 1, 2013

More about this publication?
routledg/raef/2013/00000045/00000015/art00011
dcterms_title,dcterms_description,pub_keyword
6
5
20
40
5

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
X
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more