We propose two tests for the equality of covariance matrices between two high-dimensional populations. One test is on the whole variance-covariance matrices, and the other is on offdiagonal sub-matrices which define the covariance between two non-overlapping segments of the high-dimensional...

This article tries to solve the portfolio inflation hedging problem by introducing a new class of dynamic trading strategies derived from classic portfolio insurance techniques adapted to the real world. These strategies aim at yielding higher returns on a risk-adjusted basis than regular...

The central banks introduce and implement the monetary and financial stabilities policies, going from the accurate estimations of national macro-financial indicators such as the Gross Domestic Product (GDP). Analyzing the dependence of the GDP on the time, the central banks accurately estimate...

Motivated by the latest effort to employ banded matrices to estimate a high-dimensional covariance Σ , we propose a test for Σ being banded with possible diverging bandwidth. The test is adaptive to the “large p , small n ” situations without assuming a specific parametric distribution for...

Resource misallocation can lower aggregate total factor productivity (TFP).We use microdata on manufacturing establishments to quantify the potential extent of misallocation in China and India versus the United States. We measure sizable gaps in marginal products of labor and capital across...

In recent years, the government, of African Countries has assumed major responsibilities for economic reforms and growth. In attempting to describe their economies, economists (policymakers) in many African Countries have applied certain models that are by now widely known: Linear programming...

During a long time, the Austrian Economic School was against any mathematical formalization in social and economic sciences because it would be opposed to an individualist point of view of social phenomenons. We try to find an quantitative individualism modelling way from a criticism of holist...

The transition density of a diffusion process does not admit an explicit expression in general, which prevents the full maximum likelihood estimation (MLE) based on discretely observed sample paths. Aït-Sahalia [J. Finance 54 (1999) 1361–1395; Econometrica 70 (2002) 223–262] proposed asymptotic...

In the physical world the “identity” of something is taken generally as a given; an apple is an apple; this apple is this apple. When dealing with planetary structure and extension into space, however, the problem of the planet’s “identity” in the surrounding cosmos is writ large. What...

This paper considers the problem of parameter estimation in a general class of semiparametric models when observations are subject to missingness at random. The semiparametric models allow for estimating functions that are non-smooth with respect to the parameter. We propose a nonparametric...