ON THE INDEPENDENCE OF THE SAMPLE MEAN AND TRANSLATION-INVARIANT STATISTICS FOR MATRIX NORMAL DISTRIBUTIONS

We present an explicit characterization of the joint dependency structure of an n×p matrix normal random matrix such that the p-dimensional sample mean vector is independent of all translation invariant statistics.     

Optimal Times to Contact Sample Households

Finding a suitable respondent at home is an essential and expensivecomponent of a household survey. This article reports on theresults of a study of the probabilities of finding someone aged14 or older at home and discusses the application of such datato survey design and budgeting.     

The effect of natural disaster on fertility,birth spacing,and child sex ratio: evidence from a major earthquake in India

Natural disasters can lead to significant changes in health, economic, and demographic outcomes. However, the demographic effects of earthquakes have been studied only to a limited degree. This paper examines the effect of the 2001 Gujarat earthquake on reproductive outcomes. This earthquake killed more than 20,000 people; injured 167,000; and caused massive losses to property and civic assets. Using data from two large-scale District-Level Household Surveys (2002–2004 and 2007–2008), we employ difference-in-difference and fixed-effect regression models to compare the outcomes across earthquake-affected districts and their neighboring districts during 5 years before and after the earthquake. We find that the earthquake led to significant rises in childbirth rates. It also reduced birth spacing among uneducated, tribal, and Muslim women, and the incidence of male births among rural women. We find considerable variation in the demographic effects of the earthquake across location, household socioeconomic status, and parental age and education.     

An evaluation of the tandem configuration automated guided vehicle system

The performance of a tandem automated guided vehicle (AGV) system is compared with that of conventional AGV track systems. In the tandem system the track is divided into non-overlapping, single-vehicle closed loops. Using simulation it is shown that, because of trips requiring delivery across loops, the tandem system has a higher expected travel time per load and thus a greater average time in system. When the loads are delivered within the original loop only, the tandem system has a lower average time in system than in conventional systems, although the difference is modest. Track layout appears to influence the average time in system much more than docs the dispatching rule invoked. The success of the tandem system is highly dependent on approximately even AGV utilization, which may be difficult to obtain in practice.     

Perception of HIV risk and the quantity and quality of children: the case of rural Malawi

The empirical literature on the impact of HIV on the quality (Q) and quantity (N) of children provides limited and somewhat mixed evidence. This study introduces individual HIV risk perceptions, as a predictor of mortality, into a Q–N investment model. In this model, higher maternal mortality predicts lower N, while higher child mortality predicts lower Q. Thus, the two effects together make likely negative associations between HIV and both Q and N. Based on longitudinal micro-data on mothers and their children in rural Malawi, our results suggest that higher mothers’ reported HIV risk reduces both child quality, as reflected in children’s schooling and health, and child quantity, when the perceived risk is already moderate or high. The effects are sizable and, in the case of Q (schooling and health), are found for children and teenagers, both boys and girls, while in the case of N, they are found for young and mature women.     

Job queues, discrimination, and affirmative action

If employers have different Becker-type discrimination coefficients for different demographic groups, then the implementation of affirmative action may have a differential impact on those groups. We estimate two vector autoregressive models of the U.S. economy, including the unemployment rates of four demographic groups. We find that a job queue existed before the implementation of affirmative action and that affirmative action changed the ordering of the job queue in manner that had a negative impact on nonwhite males. We find evidence that affirmative action may have increased the unemployment rate of nonwhite males by increasing their duration of unemployment.     

Television Coverage of State Government

An empirical analysis of 3,334 state and local television newsstories in 10 cities clarifies the reluctance of commercialtelevision newscasters to cover state government. Contrary towhat many television news directors assert, television's minimalattention to state government cannot be attributed to an allegednegative relationship between state government and newscastratings. Rather, it appears to stem from the high cost of obtainingfilmed coverage of state government in a timely fashion.     

ABORTION AND CRIME: UNWANTED CHILDREN AND OUT-OF-WEDLOCK BIRTHS

Legalizing abortion can either increase or decrease investments in children's human capital. This article finds that abortion increases the number of out-of-wedlock births. Using data that more directly links the criminal with age when the crime was committed, not age when arrested, and fixing the assumption in previous research that no abortions took place prior to the Roe v. Wade decision in the 45 states affected by that decision, we find consistent significant evidence that legalizing abortions increased murders by over 7%. Linear estimates indicate that legalization increased total annual victimization costs by at least $3.2 billion. ( JEL K42, K14, J24)     

Comments on Montague J. Lord's “distributional effects of international commodity price stabilization: Do the aggregate gains apply to individual producing countries?” [JPM 3:61–75 (1981)]

Lord discusses the impact of international commodity price stabilization on Latin American producing country export revenues. He correctly emphasizes that the directions and magnitudes of such effects may vary substantially across producers, depending on the degree of segmentation of the commodity markets and the nature and distribution of the shocks. However his potential contribution may be lost because of a number of inaccuracies, which I discuss under three general topics.     

The linkage effects of raw material processing in economic development: A survey of modeling and other approaches

Processing of primary raw materials has become an important and widely recommended strategy for economic development. Yet, even as the councils of many LDCs call for primary commodity producers to gain greater participation in downstream activities, there remain doubts on fundamental questions:What comparative advantage and what disadvantages do processing activities have in the LDCs?What linkages do processing activities offer?What is the potential contribution of processing to economic goal attainment in the LDCs?In this article we survey the material on processing, particularly with respect to modeling direct and indirect linkages between processing and the LDC economies. The article examines the following topics: (1) the literature on processing in economic development; (2) modeling processing linkages; and (3) outstanding questions regarding processing linkages.We focus on quantifiable linkages between the processing industry and the rest of the economy. There is also the possibility of other linkages, such as the development of entrepreneurship and management talent and technology, that are more difficult to quantify. It is important to distinguish between micro linkages, which refer to the direct impact on supplier and user sectors, and macro linkages, which include indirect general economic effects transmitted through government revenue and expenditures, the money supply, and foreign exchange availabilities.