multi product newsboy problem with limited capacity and outsourcing this paper considers a multi product newsboy system that produces multiple products for fulfilling independently uncertain demands which share the same production capacity to deal with possible shortage of limited capacity productions can be outsourced we consider two outsourcing strategies zero lead time outsourcing and nonzero lead time outsourcing the structural properties and solution procedures for the profit maximization models are developed numerical results are provided for obtaining some managerial insights

multiproduct short run hospital cost functions empirical evidence and policy implications from cross section data economists and policymakers have been interested in hospital costs and the structure of hospital technologies for several decades now early interest was focused on the possibility of scale economies which implied increased efficiency for larger hospitals 6 8 12 13 18 20 while more recent interest has been stimulated by the inflationary spiral of hospital costs 1 15 17 22 as hospital costs have risen important policy questions concerning the impact on costs of the hospitals diagnostic case mix the hospitals admitting physicians the hospitals size and the hospitals efficiency have emerged and researchers have attempted to deal with these issues within the context of increasingly complex econometric models 1 2 5 24 27 however in attempting to analyze these important policy issues researchers have been forced to make two major types of compromises on the one hand appropriate data are often not available for estimating a well specified cost function e g information on admitting physicians and diagnostic case mix are often missing so that problems of specification error often plague the econometric results conversely in using imaginative ways to deal with data problems e g weighting in patient and out patient care to form a single index of hospital services 1 27 or estimating separate cost functions for each department in the hospital 2 researchers sometimes place unrealistic and unnecessary constraints on their econometric models the purpose of this study is to analyze the impact of several of the primary hospital characteristics mentioned above on the short run costs of hospitals within a theoretically consistent framework in the following discussion we also develop the theoretical

a generalization of the endogenous grid method abstract this paper extends carroll s 2005 the method of endogenous gridpoints for solving dynamic stochastic optimization problems national bureau of economic research technical working paper 309 endogenous grid method to perform value function iteration in models with more than one control variable we propose to mix the endogenous grid method with standard value function iteration to achieve higher efficiency we illustrate the method using the stochastic neoclassical growth model with and without labor leisure choice we report important gains in efficiency that make value function iteration an attractive computational method in terms of both computing time and accuracy

budget constrained frontier measures of fiscal equality and efficiency in schooling equality and efficiency are key issues in educational reform here the authors analyze the efficiency and equality consequences of various school finance reforms using a cost indirect output distance function this function readily models multiple output production under conditions of budgetary constraint and provides a natural measure of performance that is closely related to farrell type measures of efficiency the analysis suggests that despite school district inefficiency finance reforms can affect student achievement however any potential gains in output from redistribution are dwarfed by the potential gains from increased efficiency more strikingly the analysis demonstrates that budgetary reforms designed to equalize expenditures could actually increase the inequality of student achievement

snobbery racism or mutual distaste what promotes and hinders cooperation in local public good provision a political jurisdiction may decide to cooperate in public schooling provision with its neighbors or remain independent the determinants of the consolidation decision are compared for the richer and the poorer and for the whiter and the less white jurisdiction in each potential consolidation pair property values and scale economies matter most however poorer jurisdictions prefer merging with richer ones that are less white than themselves whiter jurisdictions prefer to consolidate with less white ones of similar income less white jurisdictions are more open to consolidation with whiter ones if their incomes differ in either direction traditional club theory predictions are not supported

the wealth distribution with durable goods in the united states the distribution of houses is less egalitarian than that of earnings for the total population but these two distributions are remarkably similar for homeowners additionally housing as a fraction of total wealth decreases with the level of wealth in order to understand the different factors that account for these wealth composition patterns we introduce illiquid houses and collateral credit in a general equilibrium model of heterogeneous agents with idiosyncratic uncertainty a combination of very persistent shocks to earnings frictions in the housing market and a rental market is necessary to obtain numbers in line with the evidence

reducing the cost of demand uncertainty through accurate response to early sales traditionally fashion products have incurred high losses due to stockouts and inventory obsolence because long lead times coupled with a concentrated selling season force all or at least most production to be committed before demand information is available under a quick response system lead times are shortened sufficiently to allow a greater portion of production to be scheduled in response to initial demand we model and analyze the decisions required under quick response and give a method for estimating the demand probability distributions needed in our model we applied these procedures with a major fashion skiwear firm and found that cost relative to the current informal response system was reduced by enough to increase profits by 60 relative to the cost that would have been incurred if no response were used optimized response reduces cost by enough to roughly quadruple profits

on the determinants of school district efficiency competition and monitoring abstract a number of researchers have asserted that inefficiency in the u s school system arises from a lack of incentives for public schools to behave efficiently this paper uses a shephard input distance function to model educational production and a switching regressions estimation to explore the relationship between school district efficiency and two existing incentive mechanisms competition and voter monitoring we find evidence that ease of monitoring enhances both technical and allocative efficiency of urban school districts and that increased competition reduces allocative inefficiency in communities above a competitive threshold we find no evidence that competition is related to technical inefficiency

a multi item newsvendor problem with preseason production and capacitated reactive production abstract given items with short life cycles or seasonal demands one can potentially improve profits by producing during the selling season especially when its production capacity is substantial we develop a two stage multi item model incorporating reactive production that employs a firm s internal capacity production occurs in an uncapacitated preseason stage and a capacitated reactive stage demands occur in the reactive stage reactive capacities are pre allocated to each item in the preseason stage and cannot be changed during the reactive stage reactive production occurs during the selling season with full knowledge of demands the objective is expected profit maximization unsatisfied demand is lost the revenue salvage value and production and lost sales costs are proportional assuming no fixed costs we present a simple algorithm for computing optimal policies for a model with fixed costs for allocating preseason stage production and reactive stage capacity to product families we characterize optimal policies and develop optimal and heuristic algorithms

the method of endogenous gridpoints with occasionally binding constraints among endogenous variables we show how the method of endogenous gridpoints can be extended to solve models with occasionally binding constraints among endogenous variables very efficiently we present the method for a consumer problem with occasionally binding collateral constraints and non separable utility in durable and non durable consumption this problem allows for a joint analysis of durable and non durable consumption in models with uninsurable income risk which is important to understand patterns of consumption saving and collateralized debt we illustrate the algorithm and its efficiency by calibrating the model to us data

institutions of higher education as multi product firms economies of scale and scope a multiple output cost function is estimated for institutions of higher education in the united states employing data for 1981 82 the authors flexible fixed cost quadratic function includes three outputs undergraduate teaching graduate teaching and research grants and one input price average faculty salaries results indicate the existence of scope economies at least up to a point for both public and private institutions of higher education ray economies of scale are more pronounced in the private sector and product specific economies of scale are observed only in the public sector for research and graduate teaching copyright 1989 by mit press

returns to scale from variable and total cost functions abstract estimates of the returns to scale from a variable cost function evaluated at the actual and optimal capital stocks and a total cost function are presented the estimates generally differ depending in part upon the output at which they are evaluated

speculative production and anticipative reservation of reactive capacity by a multi product newsvendor in this paper the optimal sourcing decisions of a multi product newsvendor prior to the selling season of the products are studied to satisfy the uncertain demands the newsvendor can either utilize speculative production or anticipatively reserve capacity during the selling season when demand has become known the newsvendor can utilize its reserved capacity and reactively satisfy demand uncovered by its speculative production for the case where capacity for speculative production may be limited but potential reservation of reactive capacity is unlimited two capacity reservation settings are analyzed and compared in the first one capacity for each product has to be reserved separately while in the second setting one joint capacity reservation for all products is permitted which can then be allocated to the different products optimally during the selling season for the case of separate individual reservations the optimal strategies are analytically derived and structural insights concerning their existence are presented as the model allowing for joint reservation can not be tackled analytically in general an approximation based on an lp formulation is used through a numerical example insights on the value of the increased flexibility induced by joint reservation the cost premium acceptable for joint reservation and the relative levels of capacity reservation in the two settings are given

anticipating the consequences of school reform a new use of dea we use dea type linear programming techniques to simulate a basic component of educational reform eliminating restrictions on the allocation of school personnel our technique allows us to identify potential output gains or equivalently potential cost savings from reform we can also identify which personnel groups are likely to gain and lose under this reform when we apply our model to a sample of texas school districts we find evidence that the educational establishment has substantial economic rents to protect from school reform and that the primary beneficiaries of reform are likely to be affluent school districts with few minority students the technique which relies on the relationship between the direct and indirect distance functions can be easily generalized to measure the potential gains from removing other input restrictions such as union work rules environmental regulations or deed restrictions

saving and liquidity constraints this paper is concerned with the theory of saving when consumers are not permitted to borrow and with the ability of such a theory to account for some of the stylized facts of saving behavior the models presented in the paper seem to account for important aspects of reality that are not explained by traditional life cycle models copyright 1991 by the econometric society

the economics of schooling production and efficiency in public schools n recent years public and professional interest in schools has been heightened by a spate of reports many of them critical of current school policy these policy documents have added to persistent and long standing concerns about the cost effectiveness and fairness of the current school structure and have made schooling once again a serious public issue as in the past however any renewed interest in education is likely to be short lived doomed to dissipate as frustration over the inability of policy to improve school practice sets in this frustration about school policy relates directly to knowledge about the educational production process and in turn to underlying research on schools although the educational process has been extensively researched clear policy prescriptions flowing from this research have been difficult to derive 2 there exists however a consistency to the research findings that does have an immediate application to school policy schools differ dramatically in quality

accurate response by postponement abstract accurate response and postponement are two strategies for a firm to deal with demand uncertainty and better match supply with demand under accurate response reactive capacity could be used for customized make to order mto production according to customer demands on the other hand using postponement a firm could perform the non postponed activities speculatively and use reactive capacity only to customize the final product thereby enhancing the profitability of accurate response surprisingly existing research in the areas of accurate response and postponement does not address this potential in this paper we aim to fill this gap by proposing a stylized model for accurate response by postponement specifically we analyze a situation where a manufacturer is faced with uncertain demand for a product during a short selling season the manufacturer has three supply options first it can manufacture and offer a standardized version of the product second it can use postponement by manufacturing a standard component speculatively and customizing it once demands are revealed at the beginning of the selling season third it can produce customized products in a pure make to order fashion during the selling season this situation is modeled as an extension of a newsvendor problem our main research question is then to analyze specifically under which conditions postponement is part of the optimal supply strategy and more generally what kinds of supply strategies will arise in different model settings

analysis of trends in technical and allocative efficiency an application to texas public school districts abstract we present a new dea based method to analyze efficiency trends over time and differences across subgroups in a panel data setting we employ a result that the aggregate technical and allocative inefficiency score equals the technical inefficiency when input quantities are aggregated into a single total input cost variable and develop test procedures to evaluate the presence of allocative inefficiency we apply these methods to test for the presence of allocative inefficiency in texas school districts over 1993 99 and analyze shifts and trends in both technical and allocative inefficiencies over time for different regions our empirical results indicate the existence of statistically significant allocative inefficiencies while technical inefficiency increased over the six year sample period allocative inefficiency remained relatively stable during this period these results for the full sample obtain also when we repeat the analysis for different regions

political regime change and the real interest rate the effect of changes in policy regimes on real interest rates has important implications for financial and economic theory there is little current evidence that policy regime changes have any impact on the level of real interest rates we use large political changes as our measure of policy regime changes changes in presidential administration are more significantly correlated with real rate changes than are changes in the federal reserve chair or the mean shift points identified by garcia and perron 1996 using time series methods we also show that change of party control of congress is a significant factor explaining real rates we argue that theoretical models built on the assumptions of constant or policy invariant real interest rates are at variance with the empirical evidence

newsvendor problem with clearance pricing abstract the newsvendor nv problem assumes that the salvage clearance price at which the leftover inventory is disposed of is a given parameter of the problem in this paper we relax this assumption and consider the nv problem with the salvage clearance price as a decision variable we have drawn from the literatures on the nv problem and clearance markdown dynamic pricing to develop three stochastic models in this paper in the first model we assume that while the seasonal demand is exogenous and stochastic the end of season demand is endogenous and deterministic the second model extends the first model by assuming that the end of season demand is endogenous and stochastic finally the third model considers that both the seasonal and end of season demands are endogenous and stochastic we have provided solution procedures for solving the stochastic optimization problems we have also performed sensitivity analyses to assess the sensitivity of the optimal expected profit and order quantity to different problem parameters specifically we have found that the optimal expected profit is most sensitive to the variable cost per unit mean seasonal demand and market potential of end of season demand our models will be useful for retailers of products with a short selling season and a short end of season period for clearance sale of leftover inventory such that there is a single replenishment opportunity at the beginning of the season and a single opportunity for setting the salvage price for clearance sale based on the leftover inventory and end of season demand pattern the paper is concluded with possible directions for future research

consumption over the life cycle facts from consumer expenditure survey data this paper uses consumer expenditure survey data and a seminonparametric statistical model to estimate life cycle profiles of consumption controlling for demographics cohort and time effects we construct age profiles for total and nondurable consumption as well as expenditure patterns for consumer durables special emphasis is placed on the comparison of different approaches to control for changes in demo graphics over the life cycle we find significant humps over the life cycle for total nondurable and durable expenditures changes in household size account for roughly half of these humps bootstrap simulations suggest that our empirical estimates are tight in that standard errors are small

the cost of public schooling in new york state the role of scale and efficiency in 1978 79 cost differentials between large and small school districts are decomposed into scale and efficiency effects the analysis shows that scale economies enjoyed by large districts can come at the expense of the efficient production of educational outcomes attention is focused on the possible loss of efficiency associated with efforts to increase size by closing schools and consolidating school districts empirical evidence from new york state is presented which shows that lower levels of efficiency exist in large compared to small school districts implications for policy are explored

single versus multiple supplier sourcing strategies successful supply chain management necessitates an effective sourcing strategy to combat uncertainties in both supply and demand in particular supply disruption results in excessive downtime of production resources upstream and downstream supply chain repercussions and eventually a loss in the market value of the firm in this paper we analyze single period single product sourcing decisions under demand uncertainty our approach integrates product prices supplier costs supplier capacities historical supplier reliabilities and firm specific inventory costs a unique feature of our approach is the integration of a firm specific supplier diversification function we also extend our analysis to examine the impact of minimum supplier order quantities our results indicate that single sourcing is a dominant strategy only when supplier capacities are large relative to the product demand and when the firm does not obtain diversification benefits in other cases we find that multiple sourcing is an optimal sourcing strategy we also characterize a non intuitive trade off between supplier minimum order quantities costs and supplier reliabilities finally we examine the robustness of our results through an extensive numerical analysis of the key parameters of our model

sole versus dual sourcing in stochastic lead time s q inventory models when supply lead times are uncertain the simultaneous procurement from two sources offers savings in inventory holding and shortage costs economies are achieved if these savings outweigh the increase in ordering costs in this paper we analyze dual sourcing in the context of the reorder point order quantity inventory model with constant demand and stochastic lead times and compare it with single sourcing two cases are studied using the uniform and the exponential distributions which may be thought of as two extreme ways of representing stochastic lead times in our two vendor model the order quantity is split equally between the two vendors and the split orders are placed simultaneously when the inventory position reaches the reorder level a comparison of the total expected costs suggests that when the uncertainty in the lead times is high and the ordering costs are low dual sourcing could be cost effective

economies of scale and scope in flemish secondary schools this study estimates a multiproduct translog cost function for the entire population of 1011 flemish secondary schools in order to determine the degree of ray and product specific dis economies of scale as well as the degree of dis economies of scope three types of schools and seven major study fields can be distinguished student loads in these study fields are used as outputs produced by the schools evidence is found for ray economies of scale for the three types of schools even at output levels of 300 of the actual means although the cost elasticities of six out of seven outputs are close to zero most of the values indicating the degree of product specific economies of scale are negative suggesting diseconomies of scale however this can be explained by the considerable scope effects which are incorporated in the definition of the product specific economies of scale

economies of scale and scope and the economic efficiency of china s agricultural research system this article investigates economies of scale and scope and other potential sources of improvements in the economic efficiency of china s crop breeding an industry at the heart of the nation s food economy using data covering 46 wheatand maize breeding institutes from 1981 to 2000 we estimate cost functions for the production of new varieties at china s wheat and maize breeding institutes our results indicate strong economies of scale along with small to moderate economies of scope related to the joint production of new wheat and maize varieties cost efficiency increases significantly with increases in the breeders educational status and with increases in access to genetic materials from outside the institute

the production characteristics of local public education a multiple product and input analysis since the seminal work of baumol panzer and willig 1 economists have become increasingly interested in incorporating the multifaceted nature of real world production functions into their empirical analyses multiproducts multiple inputs and the relaxation of the long run equilibrium condition are some prime examples of major innovations in production modeling an excellent example of this innovative literature is the study by cowing and holtmann 7 that focuses on the short run production characteristics associated with the hospital services industry specifically cowing and holtmann find evidence contrary to long run equilibrium and that economies of scope are at least as important as economies of scale in the production of hospital services moreover several empirical studies relating to the production characteristics of other goods and services such as higher education 6 crime prevention 9 electric utilities 15 and airlines 5 have provided ample evidence that these pertinent factors matter from both an econometric and a policy perspective the literature concerning the production characteristics of primary and secondary education however has lagged behind in terms of incorporating more realism into the analysis typically studies concerned with primary and secondary education production 2 3 13 14 maintain that schools operate at a long run equilibrium position and produce a single output with a single input i e teachers thus assuming away factors which these other industry studies have found to be significant in fact jimenez 12 is the only study to date on local primary and secondary education production that is based on less restrictive assumptions several limitations are associated with his research however each of these limitations reduce the generality of his findings concerning the production characteristics of primary and secondary education first jimenez employs a small sample to obtain estimates of various production characteristics bringing into question the overall

stationary equilibria in asset pricing models with incomplete markets and collateral we consider an infinite horizon exchange economy with incomplete markets and collateral constraints as in the two period model of geanakoplos and zame 2002 households can default on their liabilities at any time and financial securities are only traded if the promises associated with these securities are backed by collateral we examine an economy with a single perishable consumption good where the only collateral available consists of productive assets in this model competitive equilibria always exist and we show that under the assumption that all exogenous variables follow a markov chain there also exist stationary equilibria these equilibria can be characterized by a mapping from the exogenous shock and the current distribution of financial wealth to prices and portfolio choices we develop an algorithm to approximate this mapping numerically and discuss ways to implement the algorithm in practice a computational example demonstrates the performance of the algorithm and shows some quantitative features of equilibria in a model with collateral and default