On the Structure of Sequentially Generalized Cohen-Macaulay Modules

A finitely generated module $M$ over a local ring is called a sequentially generalized Cohen-Macaulay module if there is a filtration of submodules of $M$: $M_0\subset M_1\subset ... \subset M_t=M$ such that $\dim M_0<\dim M_1< >... <\dim M_t$ and each $M_i/M_{i-1}$ is generalized Cohen-Macaulay. The aim of this paper is to study the structure of this class of modules. Many basic properties of these modules are presented and various characterizations of sequentially generalized Cohen-Macaulay property by using local cohomology modules, theory of multiplicity and in terms of systems of parameters are given. We also show that the notion of dd-sequences defined in \cite{cc} is an important tool for studying this class of modules.Comment: 28 page

Do Minimum Wage Increases Cause Inflation? Evidence from Vietnam

It is often argued that minimum wage increases can lead to increased inflation. This paper examines the impact of minimum wage increases on inflation in Vietnam during the 1994-2008 period. Inflation is measured by a monthly overall Consumer Price Index (CPI) and a monthly food CPI. It is found that the minimum wage increases did not increase inflation. Since the minimum wage increases often took place one or two months before the Vietnamese New Year festivals, observed increases in monthly inflation after the minimum wage increases were caused by increased consumption demand during the New Year festivals, not by the minimum wage increases.Minimum wages, inflation, CPI, Vietnam

H\"older continuous solutions to complex Hessian equations

We prove the H\"older continuity of the solution to complex Hessian equation with the right hand side in $L^p$, $p>\frac{n}{m}$, $1< m< n$, in a $m$-strongly pseudoconvex domain in $\mathbb{C}^n$ under some additional conditions on the density near the boundary and on the boundary data.Comment: 19 pages. Added Theorem 3.7: when the boundary is Holder continuous, there exists a Holder continuous $m$-sh extension to the domai

Targeting the Poor in Vietnam using a Small Area Estimation Method

To estimate the poverty rate at the commune level, the Ministry of Labor, Invalids and Social Affairs firstly collects information on households’ income per capita, and compares their income with a defined poverty line. A household is identified as a poor one if their income per capita is below the poverty line. Then, the poverty rate of a commune is simply the ratio of the defined poor households in that commune. This method can raise questions about the quality of the collected data on income. This paper examines the quality of expenditure data collected in this simple way. It is found that the expenditure data collected in the simple way are considerably lower than expenditure data collected using detailed questionnaires. Thus collection of expenditure or income data using simple questionnaires tends to underestimate the actual expenditure or income. For poverty targeting in small areas such as communes or districts, this paper suggests the application of this small areas estimation method

Impact Evaluation of Multiple Overlapping Programs using Difference-in-differences with Matching

Difference-in-differences with matching is a popular method in impact evaluation. Traditional impact evaluation methods including difference-in-differences with matching often deal with impact measurement of a single binary program. Imbens (1999) and Lechner (2001) extend the matching method to the case of multiple mutually exclusive programs. Frölich (2002) discusses different impact evaluation methods in the similar context. In reality, one can participate in several programs simultaneously and the programs may be overlapping. This paper discusses the method of difference-in-differences with matching in a general context of multiple overlapping programs. The method is applied to measure impacts of formal and informal credit in Vietnam using panel data from two Vietnam Household Living Standard Surveys in 2002 and 2004