estimates of the returns to quality and coauthorship in economic academia salaries of academic economists are studied to determine if individuals receive differential returns to publishing articles of varying quality and to coauthored versus single authored articles estimates based on detailed data and a flexible nonlinear least squares procedure indicate that substantial returns to quality exist and that an individual s return from a coauthored paper with n authors is approximately 1 n times that of a single authored paper

the optimal ordering policy in a dcf analysis for deteriorating items when trade credit depends on the order quantity abstract in this paper an inventory system for deteriorating items under the conditions of using the discounted cash flows dcf approach to the permissible to delay payment will be considered as a matter of fact the supplier usually is willing to provide the retailer a permissible delay of payments if the retailer orders a large quantity as a result we consider that the delay in payments depends on the quantity ordered that is when the order quantity is less than that at which the delay in payments is permitted the payment for the item must be made immediately otherwise the fixed trade credit period is permitted this paper incorporates all concepts of a dcf approach and the trade credit linked to ordering quantity and develops a new inventory model for deteriorating items to generalize jaggi and aggarwal int j prod econ 34 1994 151

urban bias rural bias or state bias urban rural relations in post revolutionary china the authors aim to evaluate the relevance of urban bias and rural bias to the chinese case they present empirical evidence on the nature and extent of differentiation in rural urban living standards examine the political basis of relevant economic policies and investigate the relationship between these policies both the changes in labour productivity in each sector and the inter sectoral savings transfers both urban and rural bias hypotheses illuminate certain dimensions of chinese development strategy but the realities of rural urban relations have been complex and analysis must be supplemented by a focus on the divide between state and society and the question of state bias

a note on eoq models for deteriorating items under stock dependent selling rate abstract in 1995 padmanabhan and vrat presented inventory models for deteriorating items with stock dependent selling rate and derived the profit functions without backlogging and with complete backlogging first this paper develops the necessary and sufficient conditions of the existence and uniqueness of the optimal solutions of the profit per unit time functions without backlogging and with complete backlogging second this paper explains that it is appropriate to use the newton raphson method to find the optimal solutions of the profit functions per unit time in both situations modelled

an inventory model for deteriorating items with stock dependent consumption rate and shortages under inflation and time discounting this paper derives an inventory model for deteriorating items with stock dependent consumption rate and shortages under inflation and time discounting over a finite planning horizon we show that the total cost function is convex with the convexity a simple solution algorithm is presented to determine the optimal order quantity and the optimal interval of the total cost function the results are discussed with a numerical example and particular cases of the model are discussed in brief a sensitivity analysis of the optimal solution with respect to the parameters of the system is carried out

partial backlogging inventory lot size models for deteriorating items with fluctuating demand under inflation abstract in this paper the traditional inventory lot size model is extended to allow not only for general partial backlogging rate but also for inflation the assumptions of equal cycle length and constant shortage length imposed in the model developed by moon et al moon i giri b c ko b 2005 economic order quantity models for ameliorating deteriorating items under inflation and time discounting european journal of operational research 162 3 773 785 are also relaxed for any given number of replenishment cycles the existence of a unique optimal replenishment schedule is proved and further the convexity of the total cost function of the inventory system in the number of replenishments is established the theoretical results here amend those in yang et al yang h l teng j t chern m s 2001 deterministic inventory lot size models under inflation with shortages and deterioration for fluctuating demand naval research logistics 48 2 144 158 and provide the solution to those two counterexamples by skouri and papachristos skouri k papachristos s 2002 note on deterministic inventory lot size models under inflation with shortages and deterioration for fluctuating demand by yang et al naval research logistics 49 5 527 529 finally we propose an algorithm to find the solution and obtain some managerial results by using sensitivity analyses

citations in economics measurement uses and impacts i describe and compare sources of data on citations in economics and the statistics derived from them constructing data sets of the post publication citation histories of articles published in the top five journals in the 1970s and 2000s i examine distributions and life cycles of citations compare citation histories of articles in different subspecialties in economics and present evidence on the history and heterogeneity of those journals impacts and the marginal citation productivity of additional coauthors i use a new data set of the lifetime citation histories of over 1 000 economists from thirty universities to rank economics departments by various measures and demonstrate the importance of intra and interdepartmental heterogeneity in productivity throughout the discussion summarizes earlier work including the impacts of citations on salaries and nonmonetary rewards and how citations reflect judgments about research quality in economics and the importance of economic ideas

rejoinder food agricultural and trade policy to the year 2000 abstract this article partly in response to fred sanderson s article pp 363 73 challenges the narrow approach of forecasting the future food situation by extrapolating current trends and the view that little can be done to improve the predicament of the poorest of the poor this article argues that we must look for ways of breaking out of the vicious circle of low income low economic demand low productivity and low levels of resource utilization

agriculture looks for shoes that fit the production responsibility system and its implications abstract by the end of 1981 problems clearly recognized within the communes included low productivity the failure to accumulate funds for modern inputs inefficient and corrupt cadres hidden unemployment inability to stimulate growth in other than major crops and disappointingly low levels of peasant incomes in many counties in north china peasants in 1980 began to divide up the collective fields on communes into smaller plots for cultivation by households and labour groups since then the face of china has been altered physically politically and organizationally by the creation of the responsibility system largely outside party control and influence document 75 of september 1980 sanctioning some form of production responsibility system was itself overtaken by events as a bewildering variety of forms emerged swamping the cadres practice was rapidly expanding beyond the theoretical discussions or pronouncements of officials like du runsheng the paper describes each of the many forms of contracting between peasant groups and the state now current in china with estimates of the relative proportions of the accounting units involved in each type table 3 new contradictions are already emerging in the changed rural set up partly because farm management problems bear similarities to those that confronted the open field strip farming of the european manor while the incentive to have more hands on family farms contradicts official chinese population policy

a production lot size inventory model for deteriorating items and arbitrary production and demand rates abstract in this paper we present a method for finding the optimal replenishment schedule for the production lot size model with deteriorating items where demand and production are allowed to vary with time in an arbitrary way and in which shortages are allowed the method is illustrated by a numerical example

trends in rankings of economics departments in the u s an update economics departments in the u s are ranked based on 1 the number of pages published in thirty six economics journals 2 publications in five of the top journals 3 output per faculty member and 4 an index of the concentration of research in a department evidence shows that the top twenty departments have generally retained their positions since the 1970s but rather large changes have occurred in departments ranked from 240 to 100 an economists hall of fame is developed listing the top fifty individual producers of research in the thirty six journal set and the top five journals

integrated inventory model for deteriorating items under a multi echelon supply chain environment abstract as the industrial environment becomes more competitive supply chain management has become essential the objective of this research is to develop a multi echelon inventory model for a deteriorating item and to derive an optimal joint total cost from an integrated perspective among the supplier the producer and the buyer a computer code is developed to derive the optimal solution a numerical example is given to illustrate the model this paper shows that the integrated approach strategy results in the lowest joint total cost as compared with the independent decision approaches

an inventory model for deteriorating items with stock dependent demand rate abstract this paper discusses an inventory model with an inventory level dependent demand rate followed by a constant demand rate for items deteriorating at a constant rate where the terminal condition of zero inventory at the end of the scheduling period has been relaxed sensitivity of the decision variables to changes in the parameter values is examined and the effects of these changes on the optimal policy are discussed in brief

negative returns to seniority new evidence in academic markets recent research has suggested that the long observed negative association between seniority and pay among college faculty largely reflects below average research productivity of senior faculty a possibility that most earlier studies did not examine overlooked in both waves of studies however is match quality because the higher quality of the faculty institutional match implied by higher seniority should all else equal result in higher salaries failure to account for match quality inflates the estimated returns to seniority indeed that positive bias the authors find is roughly equal in magnitude to the negative bias caused by failure to account for research quantity and quality when they account for both match quality and faculty research productivity in an analysis of data on economics faculty at five research universities over a 21 year period the authors estimate that holding experience and other factors constant the penalty for twenty years of seniority is 16 of salary

integrating deterioration and lifetime constraints in production and supply chain planning a survey abstract items with short lifetimes that are subject to deterioration are important in the business world research has a long tradition in integrating deterioration and value loss effects into mathematical models for inventory planning and control where such effects are understood as a general loss or shrinkage of inventory however there has been little work in the modeling of lifetime restrictions of items to prevent wastage and disposals especially in a dynamic planning context globalization and other trends extend the consideration of single companies to whole supply chains implying increased coordination and information needs this is important as planning decisions impact lead times and thus the quality of items in the whole supply chain products that exceed their useful lifetime can impose high costs due to inventory loss or the need to rework them this implies increased utilization of scarce resources e g machine time metals and or energy thereby increasing co 2 levels we survey the state of the art regarding depreciation effects and the modeling of lifetime constraints as well as a classification of models following business planning functions of the value chain a critical evaluation of approaches and their limitations is provided highlighting directions for future research

review of inventory systems with deterioration since 2001 abstract this paper presents an up to date review of the advances made in the field of inventory control of perishable items deteriorating inventory the last extensive review on this topic dates back to 2001 goyal s k and giri b c recent trends in modeling of deteriorating inventory european journal of operational research 134 1 16 since then over two hundred articles on this subject have been published in the major journals on inventory control indicating the need for a new review we use the classification of goyal and giri based on shelf life characteristics and demand characteristics contributions are highlighted by discussing main system characteristics including price discounts backordering or lost sales single or multiple items one or two warehouses single or multi echelon average cost or discounted cash flow and payment delay

fishes ponds and productivity student advisor matching and early career publishing success for economics phds i introduction research productivity is an important concern for members of the academe publishing success is important for individual departments because more productive faculty increases the department s research profile which in turn increases the department s professional reputation as evidence thursby 2000 and ehrenberg and hurst 1998 find that a department s reputation in the national research council nrc ratings increases with published research while smyth 1999 finds that pages published in the top 5 journals have a greater impact than pages published in other journals publishing success is important for individual faculty members because peer reviewed publications have long been shown to be economic currency for academic economists bratsberg ragan and warren 2003 moore newman and turnbull 1998 sauer 1988 among others research promise is important for graduate students because students with the greatest promise for productive careers are likely to receive the best initial job placements buchmueller dominitz and hansen 1999 krueger and wu 2000 long 1978 indeed according to a survey of hiring departments carson and navarro 1988 every single top 20 domestic economics program considered the quality of one s research agenda to be of moderate to great importance in the hiring decision an important question then is how to identify which factors are associated with the likelihood of having a more productive research career to date empirical studies have focused on the program from which the student graduated recent examples include collins cox and stango 2000 davis huston and patterson 2001 stock and alston 2000 this focus implicitly assumes that because only the very best students become enrolled in elite programs graduates of highly ranked programs should hold the greatest promise for publishing success 1 in support coupe 2001 and buchmueller dominitz and hansen 1999 find that students graduating from top programs are more likely to publish in core economics journals while hogan 1981 finds that students graduating from programs with more active faculty publish more journal articles before placing total faith in these results however members of the academe should ask whether such findings hold across all points in the graduate distribution or whether they are only accurate predictors on average previously published data clearly suggest the latter for instance buchmueller dominitz and hansen 1999 find that 30 of tier 1 graduates do not publish any academic articles within the first 9 yr after phd receipt while 50 do not publish any top 50 articles as defined by liebowitz and palmer 1984 in other words there is a large amount of unexplained variability in the future success of a program s graduates krueger and wu 2000 93 consequently it is likely that significant overlap exists between the performance of top program graduates and lesser program graduates with significant portions of the latter outperforming significant portions of the former with this in mind the question becomes is there a readily observable factor that is a less noisy predictor of a student s likelihood for publishing success we argue that there is during a student s postgraduate education one of the most significant influences is his or her dissertation advisor we posit that for timing reasons advisors will possess additional insight into a student s true research potential that was not available to the admission committee when deciding whether to admit the student into the program consequently we expect a student s dissertation advisor to be a more informed predictor of his or her early career productivity than the program from which he or she receives the phd 2 in other words we believe that considering the identity of a student s dissertation advisor in addition to the quality of the program from which the student receives the phd should help reduce the uncertainty inherent in predicting the student s position within the early career productivity distribution

a theory of wage dynamics a dynamic equilibrium model of long term implicit labour contracts under incomplete but symmetric information is developed workers are assumed to be risk averse and of unknown ability or productivity risk neutral firms learn as do workers about each worker s productivity by observing the worker s output over time it is shown that equilibrium contracts provide for wages which never decline with age and increase only when the worker s market value increases above his current wage in addition to characterizing the equilibrium wage contract we also derive some of its implications for the behaviour of aggregate wages across various groups of workers these implications explain some findings in the recent empirical literature on ageearnings profiles in particular our model can explain why earnings may be positively related to experience even after controlling for productivity as some empirical studies have indicated

the effect of large order quantities on expected profit in the single period model abstract the classical assumption in the single period model is that excess inventory is discounted and sold at the end of the period however the effects of large order quantities which may result in excess inventory remaining until the discount stage on the following period s demand is not considered for many products such as ski equipment and clothing customers buying large quantities of these products at the discount stage may reduce their demand for the same type of product in the next period thus having large amount of inventory to discount at the end of the period may lead to a reduction in next period s demand and therefore may reduce profit this paper investigates the effect of large order quantities on expected profit in the single period model the paper also provides an algorithm for identifying the new optimal order quantity for the problem under explicit consideration of the spell over effect of over estimating demand

the newsvendor problem in a global market optimal centralized and decentralized control policies for a two market stochastic inventory system the global markets of today offer to the style goods producer more selling opportunities and pose new challenges in production planning and coordination from a production management standpoint the opportunity to exploit the difference in timing of the selling season of geographically dispersed markets for style goods is important for improving the firm s profitability in this paper we examine the above issue with an insightful model of a producer of style goods selling the goods to two markets a primary and a secondary market with nonoverlapping selling seasons we refer to this problem as the global newsvendor problem for the above two market stochastic inventory systems we first develop optimal centralized control policies then we demonstrate the suboptimality of decentralized production control policies with the production centers at each market treated as independent profit centers and a constant transfer price being used to coordinate their production we propose as an effective alternative a decentralized production control structure with a nonlinear pricing scheme for production coordination among centers administered through an intermediate organizational unit in our modeling we explicitly consider the effects of exchange rate uncertainty on the production planning decisions

how do journal quality co authorship and author order affect agricultural economists salaries utilizing an original data set containing annual salaries and peer reviewed publication histories for 326 faculty members from top ranked ph d granting programs we examine the labor market for academic agricultural economists the results suggest that higher quality publications have a greater impact on annual earnings that sole authored articles have a higher return than multi authored articles and that no wage premium exists for being the lead author of a non alphabetic article

the impact of china s economic reforms on agricultural productivity growth this paper presents a method for assessing the relative importance of price increases and strengthened individual incentives due to the introduction of the responsibility system for the post 1978 increase in china s agricultural productivity data on post 1978 chinese agricultural performance suggest that a little over three quarters of the measured productivity increase is due to payment system changes and the remainder to price increases we also use our method to calculate incentive indices giving an estimate of the fraction of their marginal product that peasants received under the pre 1978 regime

reputation and earnings the roles of quality and quantity in academe we examine the determinants of professional reputation does quantity of exposures raise reputation independent of quality does quality of the most important exposure have extra effects on reputation in a very large sample of academic economists there is little evidence that a scholar s most influential work provides any extra enhancement of reputation quality rankings matter more than absolute quality quantity has a zero or even negative effect on proxies for reputation data on salaries however show positive effects of quantity independent of quality we test explanations for the differences between the determinants of reputation and salary jel l14 j31

scholarships citations and salaries economic rewards in economics while substantial attention has been paid to the determinants of academics earnings 5 7 8 14 15 this literature has by implication suggested that the mere fact of having spent more time in the profession and the publication of more scholarly articles and books are the major determinants of salary differences our purpose here is to introduce a new determinant the quality of one s scholarly research measured by the frequency of references to that work as an additional objective measure of productivity we expect that this proxy for the extent of a scholar s influence on the work of other researchers is rewarded by the market in addition to giving a more complete picture of the determination of salaries in academic labor markets our approach should be useful in establishing a better framework for the evaluation of issues of discrimination in such markets than has been presented before 2 9

agricultural price policy in tanzania abstract this paper examines agricultural price policy implementation and its strategic impact in tanzania over the period 1969 1980 trends in producer prices and the rural urban terms of trade are analysed by constructing weighted price and income indices for major categories of crops marketed through official channels the results indicate a substantial deterioration of real prices and incomes from crop sales during the 1970s when taken in conjunction with a concomitant deterioration in the efficiency of agricultural marketing the analysis suggests that price policy has had a major adverse impact both on peasant living standards and on the economic performance of tanzania since the mid 1960s

reputational capital and academic pay geoffrey k turnbull i introduction economists continue to have a strong interest in academic labor markets as the steady stream of earnings studies over the past several decades readily attests the academic labor market draws the attention of economists not only because it is a topic of direct personal interest but also because it presents an opportunity to examine general theories of labor markets in a context with which the researcher has intimate experience nonetheless important questions about how the market values research teaching and service remain unanswered to what extent does the market reward quality versus quantity of published research or team production in the form of co authorship furthermore how durable is reputational capital for individuals whose research productivity diminishes during their career ultimately these questions relate in one way or another to the nature of the incentive structure faced by academic economists we provide new evidence concerning the role of research quality co authorship administrative service and teaching performance in the production of reputational capital in addition we explore the question of the durability of reputational capital once some of these activities cease we assume that the quantity and quality of published research largely determines an individual s reputational capital in the external market to help us sort out the separate effects on reputational capital of both the quality and quantity of research activity we measure research quality by both journal quality and career citations employing an interactive quantity quality term a related question concerns the role of team production in building an individual s reputational capital do individuals receive differential returns to publishing single authored versus co authored research papers this is an interesting question in light of the substantial increase in co authorship over the last few decades 1 one explanation of this trend is that the academic market has presented scholars with increasing opportunities for specialization in the production of knowledge and that team production involves the combination of complementary skilled researchers if team production reflects complementarities in the production of research we should observe little difference in the returns to single versus co authored work another explanation is that co authorship involves the combination of substitute skilled researchers so that co authorship presents a way for individuals to reduce their research efforts without reducing their individual measured research output to the extent that co authorshi p represents such substitution the market should fully discount the returns to multiple authored papers in this article we also move beyond identifying the factors that enhance an individual s reputation in the market to study the question of the durability of reputational capital some individuals quit publishing once they are tenured or promoted while others experience lengthy but temporary breaks in their flow of research output we examine the potential penalties associated with gaps in research output providing the first empirical evidence concerning the durability of reputational capital for academic economists in order to ensure that our analysis deals with these issues in a way that is most relevant to a large portion of the market for academic economists we use data from several research universities but restrict the sample frame to a single discipline economics much of the previous work estimating how publications or other factors affect academic salaries typically use data from a single university with earnings equations estimated across disciplines restricting the sample to a single discipline has the additional advantage of reducing potential heterogeneity problems associated with measuring productivity across disciplines in addition our data enable us more thoroughly to explore the empirical issues in the debate since they permit more precise measures of the past and current productivity of individuals engaged in comparable work

gender and racial earnings differentials in academic labor markets this study estimates earnings differentials across racial and gender groups among college faculty and decomposes these differentials into the components attributable to differences in individual and institutional characteristics and that which remains unexplained we find that white females earn approximately 4 percent less than white males black males earn 7 4 percent more black females earn one percent more hispanic males earn 2 7 percent more hispanic females earn 1 7 percent less and asian males earn 7 7 percent more than comparable white males we also find a significant earnings penalty for being a naturalized citizen or noncitizen versus an u s born citizen

does raiding explain the negative returns to faculty seniority i introduction economists have studied various aspects of faculty mobility research shows that turnover is greater among nonunion faculty rees 1994 female faculty average slightly more employers than male faculty barbezat and hughes 2001 ginther and kahn 2004 1 the responsiveness of turnover to relative pay diminishes with rank ehrenberg kasper and rees 1991 and research productivity enhances prospects for upward mobility ault rutman and stevenson 1979 1982 coupe smeets and warzynski 2005 still questions remain unanswered where do faculty go when they leave a university how does faculty turnover vary with time at a university what percentage of faculty move upward and what percentage move downward because of tenure denials or the prospect of being turned down for tenure the present article contributes to our understanding of these issues but its primary objective was to use data on faculty mobility to provide insights on another issue returns to academic seniority the negative returns to seniority that many studies find are commonly attributed to one of two factors 2 the first view is that negative returns reflect monopsony power on the part of universities faculty with high mobility costs acquire high seniority and because they are unlikely to move they are paid less than equally productive faculty that employers view as more likely to leave a competing explanation is that highly productive faculty are raided according to this story returns to seniority are biased negatively because faculty with high seniority tend to have low unmeasured productivity the best faculty are bid away moving on to better jobs those who remain are the faculty without outside offers and the negative returns estimated for senior faculty actually reflect a penalty for low unmeasured productivity rather than a true penalty for seniority the raiding story has several implications first estimated returns to seniority should become less negative the more fully the productivity is measured second estimated returns should be less negative once we control for faculty who are bid away finally and of particular importance estimated returns to seniority should not be negative for faculty who are bid away the faculty for whom unmeasured productivity is presumably high with the right data set these hypotheses can be tested rejection of the raiding hypothesis would provide tacit evidence of monoposony in academic markets 3 this article contributes to the literature in several ways it is the first research to directly test the raiding hypothesis it provides a detailed look at faculty mobility in one segment of the academic labor market it extends and improves bratsberg ragan and warren 2003 in the following ways it expands the sample to cover three decades of faculty pay records it includes additional controls for productivity number and types of books recent and prospective articles and so forth resulting in the most complete specification of research productivity to date and it allows for heterogeneity in the seniority penalty via phd pedigree and direction of move finally it tests for the possibility that the academic job market does a better job of matching faculty and universities in recent years as might be expected because of the information revolution the sample consists of five public phd granting universities in the midwest we track all tenure track economics faculty employed in these universities over a 30 yr period we measure their productivity their pay and their mobility as such the study provides a rich and detailed investigation of one subset of economics programs it is possible that mobility may be greater in urban areas where faculty can more readily obtain alternative employment without relocating and prior research indicates that pay structures depend on the university s stature and its relative emphasis on research and teaching

an examination of the reliability of prestigious scholarly journals evidence and implications for decision makers in universities all over the world hiring and promotion committees regularly hear the argument this is important work because it is about to appear in prestigious journal x moreover those who allocate levels of research funding such as in the multi billion pound research assessment exercise in uk universities often come under pressure to assess research quality in a mechanical way by using journal prestige ratings this paper s results suggest that such tendencies are dangerous it uses total citations over a quarter of a century as the criterion the paper finds that it is far better to publish the best article in an issue of a medium quality journal like the oxford bulletin of economics and statistics than to publish the worst article or often the worst 4 articles in an issue of a top journal like the american economic review implications are discussed

retailer s optimal pricing and lot sizing policies for deteriorating items with partial backlogging pricing is a major strategy for a retailer to obtain its maximum profit therefore in this paper we establish an economic order quantity model for a retailer to determine its optimal selling price replenishment number and replenishment schedule with partial backlogging we first prove that the optimal replenishment schedule not only exists but also is unique for any given selling price next we show that the total profit is a concave function of p when the replenishment number and schedule are given we then provide a simple algorithm to find the optimal selling price replenishment number and replenishment timing for the proposed model finally we use a couple of numerical examples to illustrate the algorithm

ration subsidies and incentives in the pre reform chinese commune a central feature of the egalitarianism said to have undermined work incentives in chinese agricultural produ ction teams during the 1960s and 1970s was the distribution of grain rations independently of work contribution this paper analyzes two m odels of grain rationing one drawn from existing theoretical literat ure and the other perhaps more closely based on chinese practice it finds that a scheme of the type commonly depicted was more costly to operate but provided better incentives to labor poor households unde r both schemes however the scope for material incentives was reduce d by grain ration guarantees and was smaller the poorer the team copyright 1988 by the london school of economics and political science

are there gender differences in the job mobility patterns of academic economists labor economic theory posits that job mobil ity should affect worker salaries the degree to which this holds for academic faculty has received considerable attention prior empirical studies have estimated log wage regressions that control for both years of total work experience and years of seniority at the current institution in an effort to determine whether negative returns to seniority exist in academic labor markets for example bernt bratsberg james ragan and jim warren 2003 and william moore robert turnbull and geoffrey newman 1998 for aca demic economists michael ransom 1993 kevin hallock 1995 and emily hoffman 1976 for specific institutions debra a barbezat and michael r donihue 1998 and barbezat 1989 for

urbanization and underdevelopment a global study of modernization urban bias and economic dependency the causes and effects of 3rd world urbanization have been addressed in theories of modernization urban bias and economic dependency but no single cross national study has tested the arguments advanced by all 3 theories this paper uses panel regression analysis to assess the validity of the 3 perspectives in 61 underdeveloped countries between 1960 and 1980 the modernization theory asserts that industrial employment attracts people to urban areas where they work in modern sector employment that facilitates national economic expansion the urban bias theory posits that the disparity in welfare between country and city increases rural to urban migration and thereby expands both urbanization and service informal employment dependency and world system arguments assert that foreign investment promotes both urbanization and service informal labor with foreign investment in agriculture pushing farmers townward and foreign investment in urban manufacturing pulling them there results suggest that underdeveloped nations are experiencing a gradual transition from an agrarian to a service and informal economy a transformation that impedes economic expansion unfavorable agricultural conditions alone will not push rural citizens to urban areas 2 theories help explain the relationship between relatives urbanization and economic growth if future studies of urbanization and underdevelopment are going to be useful then they must transcend current theoretical and ideological particularism

revisiting the seniority wage effect for faculty abstract this study uses 1999 national data to derive estimates of the effect of seniority on faculty salaries seniority has a positive effect on salary but varies by union status rank job mobility and inclusion of faculty productivity measures

negative returns to seniority and job mobility across the program quality distribution are top public phd granting programs different we analyze a unique data set containing annual salary and detailed job and publication histories for a sample of 1 009 faculty members drawn from 53 public ph d granting economics departments empirical results suggest that all else equal 1 statistically significant negative returns to seniority exist within lower ranked but not top 15 programs 2 more frequent movers observe statistically higher annual salaries in lower ranked but not top 15 programs and 3 for each level of seniority faculty in top 15 programs are more likely to move at any point in the career than faculty in lower ranked programs

seniority wages and productivity a turbulent decade why does a worker s wage tend to grow with seniority in the firm and what does this have to do with productivity two decades ago neoclassical labor economists thought that the theory of human capital provided a good answer to this question the last decade has however been one of puzzles and doubt at this point few would give an unambiguous answer and much hinges on the answer an attractive feature of human capital theory is that it yields a consistent and coherent explanation for several aspects of the employer employee relationship for example seniority systems layoff policies that vary with skill and the relationship between tenure and turnover can be explained in terms of human capital the fact that these explanations are connected leads however to something like a domino effect doubts about one cast doubt on the others if the human capital explanation for the wage seniority relationship is flawed then human capital explanations for other phenomena may require reevaluation in addition an important body of empirical research is built around the assumption that at any point in time a person s wage indicates the person s productivity included here is the extensive literature on the human capital earnings function as well as work on labor demand market discrimination and compensating differentials that assumption has become controversial in recent years in part because implicit contract theories predict that compensation will be redistributed over the period of the contract if a person s spot wage has little to do with spot productivity but rather is an instrument of a complex insurance or deferred compensation scheme then a reassessment of the empirical research may be necessary

trigger strategies in chinese agricultural teams in this paper the reasons why chinese agricultural teams could not reply on the threat of internal effort response to solve incentive problems are investigated the detrimental effects of state extractive agricultural policies the basic needs program and cultural revolution era ideology on the dynamic self enforcing mechanism in chinese teams are analysed using the data on the teams of a moderately prosperous commune during the period 1970 76 the author estimates the discount factor and the impact of the trigger strategies on workers effort decisions it is found that the estimates of the discount factor and the trigger strategy effect are significantly greater than zero in some periods but not large enough to eliminate the need for monitoring

outside offers and the gender pay gap empirical evidence from the uk academic labour market using a unique data source on academic economist labour market experiences we explore gender pay and promotions in addition to earnings and productivity measures we have information on outside offers and perceptions of discrimination we find both a gender promotions gap and a within rank gender pay gap a driving factor may be outside offers men receive more outside offers than women of comparable characteristics and gain higher pay increases in response this may arise due to discrimination we find that perceptions of discrimination and also outside job applications correlate with an individual receiving earnings below that expected given their characteristics

deterministic models of perishable inventory with stock dependent demand rate and nonlinear holding cost this paper deals with an extended eoq type inventory model for a perishable product where the demand rate is a function of the on hand inventory the traditional parameters of unit item cost and ordering cost are kept constant but the holding cost is treated as i a nonlinear function of the length of time for which the item is held in stock and ii a functional form of the amount of the on hand inventory the approximate optimal solution in both the cases are derived computational results are presented indicating the effects of nonlinearity in holding costs

an optimal replenishment policy for non instantaneous deteriorating items with stock dependent demand and partial backlogging abstract in this study we consider a problem of determining the optimal replenishment policy for non instantaneous deteriorating items with stock dependent demand in the model shortages are allowed and the backlogging rate is variable and dependent on the waiting time for the next replenishment the necessary and sufficient conditions of the existence and uniqueness of the optimal solution are shown as the special cases the results for the models with instantaneous or non instantaneous deterioration rate and with or without shortages are derived further we analytically identify the best circumstance among these special cases based on the minimum total relevant cost per unit time sensitivity analysis of the optimal solution with respect to major parameters is carried out finally four numerical examples are presented to demonstrate the developed model and the solution procedure

an eoq model with ramp type demand rate time dependent deterioration rate unit production cost and shortages an order level inventory system for deteriorating items has been developed with demand rate as a ramp type function of time the finite production rate is proportional to the demand rate and deterioration rate is time proportional the unit production cost is inversely proportional to the demand rate the model with no shortage case in inventory is first solved the inventory shortage is discussed next results are illustrated with two numerical examples for two models along with its sensitivity

the evolution of the scientific productivity of highly productive economists this paper studies the evolution of research productivity of a sample of economists working in the best 81 departments in the world in 2007 the main novelty is that in so far as a productivity distribution can be identified with an income distribution we measure productivity mobility in a dynamic context using an indicator inspired in an income mobility index suggested by fields 2010 for a two period world productivity is measured in terms of publications weighted by the citation impact of the journals where each article is published in the periodical literature we study the evolution of average productivity productivity inequality the extent of rank reversals and productivity mobility for seven cohorts as well as the population as a whole we offer new evidence confirming previous results about the heterogeneity of the evolution of productivity for top and other researchers however the major result is that contrary to what was expected for our sample of very highly productive scholars the effect of rank reversals between the two periods on overall productivity mobility offsets the effect of an increase in productivity inequality from the first to the second period in the youngest five out of seven cohorts jel a11 a12 b41 d63 i32

fame and the fortune of academic economists how the market rewards influential research in economics we analyze the pay and position of 1 009 faculty members who teach in doctoral granting economics departments at fifty three large public universities in the united states using the web of science we have identified the journal articles published by these scholars and the number of times each of these articles has been subsequently cited in published research articles we find that research influence as measured by various measures of total citations is a surprisingly strong predictor of the salary and the prestige of the department in which professors are employed we also examine how coauthorship is rewarded by the market

an optimal production inventory model for deteriorating items with multiple market demand the global markets of today offer more selling opportunities to the deteriorating items manufacturers but also pose new challenges in production and inventory planning from a production management standpoint opportunities to exploit the difference in the timing of the selling season between geographically dispersed markets for deteriorating items are important to improving a firm s profitability in this paper we examined the above issue with an insightful production inventory model of a deteriorating items manufacturer selling goods to multiple markets with different selling seasons we also provided a solution procedure to find the optimal replenishment schedule for raw materials and the optimal production plan for finished products a numerical example was then used to illustrate the model and the solution procedure finally sensitivity analysis of the optimal solution with respect to major parameters was carried out

academic pay in the united kingdom and the united states the differential returns to productivity and the lifetime earnings gap this paper estimates earnings functions for two samples of u k and u s academic economists despite significant differences in compensation schemes a comparably specified human capital earnings model does a good job explaining earnings variations for academic economists in both countries our estimates suggest that rewards for research are more immediate and direct in the united states because of the national salary scale the payoffs to experience and seniority are greater and the payoffs to research are lower in the united kingdom than in the united states after adjusting for productivity and demographic factors we find that u s economists are paid approximately 40 more than otherwise equivalent economists in the united kingdom simulating career age earnings profiles for both markets we find that the earnings gap widens with experience for relatively productive research economists and may even narrow with age for relatively less productive research economists nevertheless the cumulative lifetime earnings foregone are substantial for research and nonresearch economists in the united kingdom

citations or journal quality which is rewarded more in the academic labor market research quality can be evaluated from citations or from the prestige of journals publishing the research we relate salary of tenured university of california uc economists to their lifetime publications of 5 500 articles and to the 140 000 citations to these articles citations hardly affect salary especially in top ranked uc departments where impacts of citations are less than one tenth those of journals in lower ranked departments and when journal quality is less comprehensively measured effects of citations on salary increase if journal quality is just measured by counting articles in journal tiers apparent effects of citations are overstated jel a14 j44

which journal rankings best explain academic salaries evidence from the university of california the ranking of an academic journal is important to authors universities journal publishers and research funders rankings are gaining prominence as countries adopt regular research assessment exercises that especially reward publication in high impact journals yet even within a rankings oriented discipline like economics there is no agreement on how aggressively lower ranked journals are down weighted and in how wide is the universe of journals considered moreover since it is typically less costly for authors to cite superfluous references whether of their own volition or prompted by editors than it is to ignore relevant ones rankings based on citations may be easily manipulated in contrast when the merits of publication in one journal or another are debated during hiring promotion and salary decisions the evaluators are choosing over actions with costly consequences we therefore look to the academic labor market using data on economists in the university of california system to relate their lifetime publications in 700 different academic journals to salary we test amongst various sets of journal rankings and publication discount rates to see which are most congruent with the returns implied by the academic labor market jel a14 i23 j44

seniority and monopsony in the academic labor market workers with high seniority usually have higher wages than workers with low seniority and the same total labor marke t experience in contrast the results of this paper indicate that higher seniority is associated with lower salaries for university professors the author documents this finding for national surveys a nd individual institutions and explains it as due to monopsonistic discrimination by employers copyright 1993 by american economic association

seniority and monopsony in the academic labor market comments this paper further explores the work of both michael ransom and emily hoffman who have written on monopsony in the academic labor market using data from university of massachusetts at amherst umass from 1989 this comment has three principal findings i the return to seniority at umass is positive at least for low levels of seniority which is contrary to ransom s results ii faculty hired with tenure have significantly higher salaries which supports the ransom monopsony hypothesis and iii sex discrimination as described by hoffman is much lower in 1989 than it was 15 years prior

the structure and contradictions of productive relations in socialist agrarian reform a framework for analysis and the chinese case this article attempts to develop a complex analytical framework for analysing socialist agrarian reform and to apply it to the case of post mao china perhaps the most sweeping agrarian reform in the history of socialism the purpose of doing so is to disaggregate the complex changes which have been wrought under the responsibility systems in order to get a more nuanced sense of what has and has not changed how the various parts fit together and where the axes of contradiction posed by the reform may lie this analytical framework may also be of use in comparative analysis of socialist agriculture though that enterprise is not attempted here one basic argument of this study is that the responsibility systems of the recent chinese reforms are neither socialist nor capitalist but something distinctive whose potentially heterogeneous elements must be identified disaggregated analysed one by one and then reconstituted in order to expose their nature dynamics and contradictions

do academic salaries decline with seniority this article reexamines the negative seniority earnings relationship for academic economists the empirical results show that the anomalous negative seniority effect found in earlier academic market studies holds in the absence of direct measures of research productivity the negative effect however eventually disappears as more comprehensive measures of publishing citations and other productivity measures are included in the wage equation to control for the quantity and quality of faculty productivity faculty with greater seniority appear to be rewarded relatively less simply because many have been relatively less productive than their colleagues with less seniority at similar stages in their careers

an economic order quantity model for deteriorating items with partially permissible delay in payments linked to order quantity abstract to attract more sales suppliers frequently offer a permissible delay in payments if the retailer orders more than or equal to a predetermined quantity w in this paper we generalize goyal s k 1985 eoq under conditions of permissible delay in payments journal of the operational research society 36 335 338 economic order quantity eoq model with permissible delay in payment to reflect the following real world situations 1 the retailer s selling price per unit is significantly higher than unit purchase price 2 the interest rate charged by a bank is not necessarily higher than the retailer s investment return rate 3 many items such as fruits and vegetables deteriorate continuously and 4 the supplier may offer a partial permissible delay in payments even if the order quantity is less than w we then establish the proper mathematical model and derive several theoretical results to determine the optimal solution under various situations and use two approaches to solve this complex inventory problem finally a numerical example is given to illustrate the theoretical results