M-estimator-based robust estimation of the number of components of a superimposed sinusoidal signal model

In this paper, we consider the problem of estimating the number of components of a superimposed nonlinear sinusoids model of a signal in the presence of additive noise. We propose and provide a detailed empirical comparison of robust methods for estimation of the number of components. The proposed methods, which are robust modifications of the commonly used information theoretic criteria, are based on various M-estimator approaches and are robust with respect to outliers present in the data and heavy-tailed noise. The proposed methods are compared with the usual non-robust methods through extensive simulations under varied model scenarios. We also present real signal analysis of two speech signals to show the usefulness of the proposed methodology.     

Effect of adjustment for sex composition in the measurement of fertility on intrinsic rates

The inconsistencies inherent in the one-sex models created a need for the construction of what are known as marriage functions, especially for the measurement of fertility. But attempts to develop marriage functions have been frustrated by the inability of the proposed functions to meet certain consistency conditions and also by difficulties in empiracally determining function parameters. Among several functions proposed so far, Das Gupta's (1972) "effective population" deserves special mention. He uses both sexes in its formulation, and has shown that the constancy of fertility rates based on such a function together with the constancy of survivorship probabilities of both sexes would result in a stable population. It is suggested in this article that the major source of the problem in a two-sex model seems to be the requirement that the model has to be specific both for sex and age. The ideal of incorporating the relative composition of one sex in the age-specific rates of the other, thereby creating a function dependent on both sexes, is advanced in this article. Such functions, defined explicitly for births, can be easily translated into age-specific birth rates. In addition to simplicity in the definition and form, the conditions leading toward stability can also be established. Interestingly enough, the intrinsic rate for this two-sex model lies in the interval determined by the rates obtained from the two one-sex models.     

Economic Growth,Health and Poverty: An Exploratory Study for India

This article analyses the possible links between economic growth, poverty and health, using panel data for the Indian states. The findings indicate that, though growth tends to reduce poverty, significant improvements in health status are also necessary for poverty to decrease. Also, economic growth and health status are positively correlated and have a two‐way relationship, suggesting that better health enhances growth by improving productivity, and higher growth allows better human capital formation. Health expenditure is an important determinant of both higher growth and better health status, and is therefore a key tool available to policy‐makers. Among other exogenous variables, literacy and industrialisation seem to improve both health outcomes and growth, and to reduce poverty.     

On approximate least squares estimators of parameters of one-dimensional chirp signal

Chirp signals are quite common in many natural and man-made systems such as audio signals, sonar, and radar. Estimation of the unknown parameters of a signal is a fundamental problem in statistical signal processing. Recently, Kundu and Nandi [Parameter estimation of chirp signals in presence of stationary noise. Stat Sin. 2008;75:187–201] studied the asymptotic properties of least squares estimators (LSEs) of the unknown parameters of a simple chirp signal model under the assumption of stationary noise. In this paper, we propose periodogram-type estimators called the approximate least squares estimators (ALSEs) to estimate the unknown parameters and study the asymptotic properties of these estimators under the same error assumptions. It is observed that the ALSEs are strongly consistent and asymptotically equivalent to the LSEs. Similar to the periodogram estimators, these estimators can also be used as initial guesses to find the LSEs of the unknown parameters. We perform some numerical simulations to see the performance of the proposed estimators and compare them with the LSEs and the estimators proposed by Lahiri et al. [Efficient algorithm for estimating the parameters of two dimensional chirp signal. Sankhya B. 2013;75(1):65–89]. We have analysed two real data sets for illustrative purposes.     

PARTIES,POLITICS, AND REGULATION: EVIDENCE FROM CLEAN AIR ACT ENFORCEMENT

Does local Federal regulation respond to the preferences of local Congressional representatives? For example, do Republican Congressmen reduce local enforcement of Clean Air laws in their districts? We use facility‐level panel data on Clean Air Act inspections over 1989–2005 to study the causal effect of a Congressman's party affiliation on local enforcement. Random assignment of electoral outcomes is obtained with a Regression Discontinuity design. We find that new Republican (vs. Democratic) Representatives significantly depress inspection rates for local polluting facilities in the first year after their election. (JEL D73, Q52, Q53)     

On Estimating the Expectation of Life at Old Ages: Reply to Professor Coale

In 1758, an article containing the view that resources limit population growth was published in Copenhagen. This paper gives a short presentation of the author Otto Diderich Lütken's life and literary production. His radical views on the question of population are given, and a comparison is made with the theories of Thomas Robert Malthus. A brief account of his views on other economic issues is also presented. The literature concerning his writings is reviewed. A discussion of who influenced him, and of his influence on others, ends this paper.     

Some Further Issues Concerning Likelihood Inference for Left Truncated and Right Censored Lognormal Data

The maximum likelihood estimates (MLEs) of the parameters of a two-parameter lognormal distribution with left truncation and right censoring are developed through the Expectation Maximization (EM) algorithm. For comparative purpose, the MLEs are also obtained by the Newton–Raphson method. The asymptotic variance-covariance matrix of the MLEs is obtained by using the missing information principle, under the EM framework. Then, using asymptotic normality of the MLEs, asymptotic confidence intervals for the parameters are constructed. Asymptotic confidence intervals are also obtained using the estimated variance of the MLEs by the observed information matrix, and by using parametric bootstrap technique. Different confidence intervals are then compared in terms of coverage probabilities, through a Monte Carlo simulation study. A prediction problem concerning the future lifetime of a right censored unit is also considered. A numerical example is given to illustrate all the inferential methods developed here.     

On the nature of Suppes–Sen maximal paths in an aggregative growth model

This article investigates the nature of paths in the standard neoclassical aggregative model of economic growth that are maximal according to the Suppes–Sen grading principle. This is accomplished by relating such paths to paths which are utilitarian maximal when an increasing (but not necessarily concave) utility function evaluates each period’s consumption. Dynamic properties of Suppes–Sen maximal paths, which lie entirely above or entirely below the golden-rule, are analyzed. An example is presented in which an explicit form of a consumption function is described, which generates only Suppes–Sen maximal paths. This consumption function is shown to generate consumption cycles, and violate the Pigou–Dalton transfer principle.     

Efficient allocation of heterogenous commodities with balanced transfers

In this article, we characterize heterogenous commodities allocation problems where an efficient rule can be implemented in dominant strategies with balanced transfers. We show that the class of such problems is non-trivial and that the associated difference domain is one-dimensional. If the domain satisfies convexity, there exists a permutation of the objects for which the associated difference domain is a straight line passing through the origin with positive slope. An interesting feature of the domains is that at most two orderings of the commodities are permissible and, in particular, one ordering must be the reverse of the other.     

On Testing Exponentiality against NBAFR Alternatives

In this article, we propose an interesting approach for testing exponentiality against NBAFR alternatives. A measure of deviation from exponentiality has been derived on the basis of an inequality which we have proved. A test statistic has been constructed using density estimators and its asymptotic normality established. The consistency of the said test is also proved.