the effect of income on child development this study presents estimates of the effect of parental income on children s cognitive social and emotional development the effect of current income is small especially when income is treated as endogenous the effect of permanent income is substantially larger but relatively small when compared to the magnitude of recent policy induced changes in income family background characteristics play a more important role than income in determining child outcomes policies that affect family income will have little direct impact on child development unless they result in very large and permanent changes in income

women s work sibling competition and children s school performance this research offers an interpretation of the relationship between fertility child spacing family resources and market work by mothers and the subsequent cognitive skills of grade schoolers as reported by their teachers first an approach to fertility as the outcome of a deliberate choice process is developed and then empirical evidence from a small panel of u s households first interviewed in 1975 76 when they had preschool children is presented in a 1981 82 reinterview a supplementary project was that of obtaining teacher ratings of school performance of individual children large family size as measured by the number of siblings of given age and sex in the household during preschool years in 1975 76 has an important negative impact on the child s subsequent grade school performance boy siblings in nearby age ranges have the most negative impact on performance while teenage siblings of either sex have no systematic adverse effect parental resources as measured by income education child care time and a mother s reduced market time are associated with greater cognitive skills and can offset the apparent disadvantage of having siblings in nearby age intervals there appears to be a significant tradeoff between a market career and a home career for women women who have more children spaced over wider age intervals and who devote more time to child care and less to market work presumably get more benefits from their home career in the form of enhanced child development on the other hand full time market work i e hours in the labor market for pay is important for earnings growth of the mother mary corcoran greg duncan and michael ponza 1983 and family income has a favorable effect on school performance so the apparent choices facing women are more equivocal

more mortgages lower growth in newly collected data on 46 economies over 1990 2011 we show that financial development since 1990 was mostly due to growth in credit to real estate and other asset markets which has a negative growth coefficient we also distinguish between growth effects of stocks and flows of credit we find positive growth effects for credit flows to nonfinancial business but not for mortgage and other asset market credit flows by accounting for the composition of credit stocks and for the effect of credit flows we explain the insignificant or negative growth effects of financial development in recent times what was true in the 1960s 1970s and 1980s when the field of empirical credit growth studies blossomed is no longer true in the 1990s and 2000s new bank lending is not primarily to nonfinancial business and financial development may no longer be good for growth these trends predate the 2008 crisis they prompt a rethink of the role of banks in the process of economic growth jel e44 o16 o40 c33

the effect of family background on children s level of schooling attainment in spain this paper provides microeconomic estimates of the role played by family background in determining children s level of schooling attainment in spain we use an ordered logit model to explore the effects of family background and other supply factors on the probability of various educational outcomes our estimates are based on household data obtained from the ecvt living and working conditions survey ministerio de economia y hacienda 1985 a spanish nation wide household survey conducted at the end of 1985 in general and given the spanish capital constraints parental income social class and family size explain children s level of schooling these results are consistent with those of the literature that focuses on the role of family background in determining schooling attainment

shirking or productive schmoozing wages and the allocation of time at work this study uses detailed time diaries from household surveys for 1975 and 1981 to examine how changes in the use of time on the job affect earnings among nonunion workers the marginal minute of break time apparently increases earnings but not as much as does the marginal minute of work time among union workers additional time in unscheduled breaks appears to be associated with significantly higher earnings though other break time is not the author concludes that further growth in on the job leisure would reduce productivity that monitoring workers would yield returns to the firm but that entirely eliminating breaks would be counterproductive

does the birth order affect the cognitive development of a child this article investigates the link between position in the birth order and early scholastic ability using matched mother child data from the national longitudinal survey of youth 1979 cohort nlsy79 i find that being the first born is beneficial even after controlling for nonlinear effects of family size and child characteristics the verbal ability of first borns is about one tenth of a sd higher than for children in the middle of the birth order there is no evidence that last borns fare better than intermediate children the first born advantage is confirmed by estimates from within family variation models and i argue that the findings are consistent with the resource dilution hypothesis

birth order schooling and earnings birth order effects are posited by many to affect earnings and schooling we show how such effects can be interpreted to shift either the earnings possibility frontier for siblings or parental preferences we find empirical evidence for birth order effects on age adjusted schooling and on earnings for young u s adults though the latter is not robust for all specifications the examination of intrahousehold allocations suggests that these birth order differences occur despite parental preferences or prices by birth order favoring later borns apparently because of stronger endowment effects that favor firstborns

a longitudinal analysis of white women s wages according to human capital theory women s work participation decisions will strongly affect their wages and wage growth we test human capital predictions about how labor force withdrawals both past and prospective part time work experience and working in male rather than in female jobs affect wages and wage growth for white women we do this by estimating a wage change model for the years 1967 1979 for a national sample of white women we find that wages drop immediately following withdrawals but that this is followed by a rapid wage growth so that the net loss in wages from dropping out of the labor force is small we further find that wage growth is not significantly lower in female than in male jobs but that part time work experience does not lead to significant wage growth in either male or female jobs

home alone supervision after school and child behavior as female participation in the labor force continues to grow in the us so too does reliance on non parental child care however the high cost of child care has impeded the ability of many working mothers to find sufficient child care for their children as a result as recently as 1998 over eight million children ages five to 14 spent time without adult supervision on a regular basis in the us i examine the effect of the lack of adult supervision after school on a panel of school age children using ordinary least squares and fixed effect estimation i find that children with adult supervision are less likely to skip school use alcohol or marijuana steal something or hurt someone these findings suggest that expanding after school or child care programs typically geared to preschool age children to accommodate more school age children may have important consequences for their human capital development and labor market outcomes later in life

infant health and the labor supply of mothers this study examines the association between maternal employment and infant feeding and the health of children and the role of prices wages and other exogenous factors in influencing the association in the philippines data were obtained from the 1983 86 cebu longitudinal health and nutrition survey of 2868 women who were permanent residents of the sample areas and had given birth to a single live child in metro cebu during 1983 84 analysis is based on the conceptual framework in which infant feeding and labor supply are jointly chosen to maximize the utility subject to time budget and health production function constraints findings indicate that the labor supply of the mother had little direct effect on infant health when prices wages and other exogenous factors are taken into account maternal wage rates and prices of key foods affected labor supply and infant feeding and care women with better wage offers were more likely to work and to have healthier infants maternal labor supply only had statistically significant effects on infant health when occupation was accounted for it is suggested that women in developing countries should not be discouraged from working womens earnings increase their ability to pay for food and breast milk substitutes that contribute to healthy infants the authors suggest that other health outcomes such as infant morbidity and mortality could be examined or substitutions for other feeding patterns and child care options

an s 1 s inventory system with emergency orders in this paper we develop an approximate model of an inventory control system in which there exist two options for resupply with one having a shorter lead time we assume that demand and the fixed ordering costs are small relative to the holding cost so that a one for one ordering policy is appropriate we consider a policy for placing emergency orders that uses information about the age of outstanding orders we derive the steady state behavior of this policy and present some computational results

an approximate policy for a dual sourcing inventory model with positive lead times and binomial yield this paper studies the inventory system of a retailer who orders his products from two supply sources a local one that is responsive and reliable but expensive and a global one that is low cost but less reliable the deliveries from the global source only partially satisfy the quality requirements we model this situation with a dual sourcing inventory model with positive lead times and random yield we propose a dual index order up to policy dop based on approximating the inventory model with an unreliable supplier by a sequence of dual sourcing models with reliable suppliers and suitably modified demand distributions numerical results show that the performance of this heuristic is close to that of the optimal dop moreover we extend the heuristic to models with advance yield information and study its impact on the total inventory costs

credit constraints and gdp growth evidence from a natural experiment abstract before 1998 texas was the only state that greatly restricted home equity loans and cash out refinancing for non housing consumption such borrowing was authorized in texas for the first time through a constitutional amendment in 1998 using state level panel data and recently developed synthetic control methods based on machine learning we find that the texas constitutional amendments relaxing credit constraints had an insignificant impact on gdp growth our findings have important policy implications for the stimulative effect of easier home equity access on gdp growth

birth order family size and achievement family structure and wage determination do birth order and the size of one s childhood family influence environment thereby potentially affecting future achievement this article investigates the hypothesis that they do presenting two major empirical findings first neither birth order nor childhood family size significantly influences the level or growth rate of wages a result that is consistent with previous research second family size is both a statistically and economically significant determinant of women s employment status women from small families work less than women from large families when they are young and more than women from large families when they are more mature

an inventory model with poisson demands and emergency orders abstract in this paper we explicitly consider the opportunity to use an emergency supply mode to hedge against demand uncertainty when replenishing a single item inventory normal orders with a relatively long and constant lead time are controlled by a standard r q policy these orders can only be issued when no other orders are outstanding when a normal order is outstanding emergency orders are controlled by a reorder point r j and an order up to level u j where j is a measure of the time remaining until the normal order is delivered the emergency orders have a short lead time and they may also have different ordering costs compared to normal orders demands not satisfied immediately from inventory are backordered we formulate a long run average cost model that includes ordering costs for the two types of orders backordering costs and holding costs backordering costs are considered both as a unit based cost and as a cost rate a tailor made policy iteration algorithm is designed and utilized to minimize the inventory cost rate with state dependent emergency orders for comparisons an algorithm for finding a best simple emergency order policy is also implemented simulation is used to check the validity of our model numerical results are presented for a set of parameter variations and compared to results without emergency orders as well as to results from an earlier model in the literature our results show that substantial cost savings might be obtained by using emergency orders especially when backordering costs are high however the marginal gains are fairly small if state dependent emergency orders are used instead of a simple emergency order policy

the finance and growth nexus revisited we find that an expansion of credit has a positive effect on per capita output growth only up to a point beyond this threshold the impact of finance on growth is not statistically significant anymore we show however that the estimated non linear relationship may stem from the omission of factors not considered in the literature so far these factors may have a negative impact on growth in mature financial systems and include the magnitude of financial cycles as well as the importance of non intermediation activities in banks business models

birth order and risky adolescent behavior i introduction there is a widespread belief that birth order is an important determinant of personality intelligence and economic success this belief is supported by a number of recently published popular books each with its own approach to the topic leman 2001 16 18 for instance argues that firstborns are more highly motivated to achieve than later borns and as a consequence often fill positions of high authority or achievement in contrast wallace 1999 18 worries that firstborns go through life feeling like they cannot measure up to the high standards their parents expected lacking in confidence they might drop out and refuse to compete altogether 1 although there is an intuitive appeal to some of these theories the weight of evidence suggests that birth order effects of this nature either do not exist or are difficult to measure using the standard approaches of social scientists a large number of empirical studies have examined the effect of birth order on test scores education and earnings see olneck and bills 1979 blake 1981 hauser and sewell 1983 behrman and taubman 1986 kessler 1991 and hanushek 1992 taken together their results suggest that after properly controlling for family size birth order explains little variation in these conventional measures of success another more recent strand of research in this area examines whether the sex composition of an individual s siblings affects academic achievement as measured by years of education in a well known article butcher and case 1994 present evidence that females raised with brothers go on to receive more education on average than that of females raised with at least one sister however even this relatively modest albeit unexpected finding has been called into question by subsequent studies note kaestner 1997 and hauser and kuo 1998 using data on adolescents aged 12 through 17 we investigate the relationship between birth order and a number of behaviors that have been for the most part ignored in this literature these behaviors include the probability that an individual smoked cigarettes used substances such as marijuana or alcohol engaged in sexual activity or committed any one of a series of crimes in contrast to what most empirical studies have found we find strong evidence that birth order is related to many of the outcomes under study we also show that at least one birth order difference can last into early adulthood if not beyond although it is difficult to isolate the precise routes through which birth order affects the behavior of adolescents our results are consistent with the idea that peer influences play an important role ii why birth order effects might exist researchers working in this area have long speculated that birth order might be related to child outcomes through parental investments in their offspring becker and tomes 1976 posit a model in which parents devote more financial resources to children with lower innate ability 2 if as suggested by behrman and taubman 1986 and kessler 1991 genetic endowments favor earlier born children this model would predict offsetting financial investments in later borns under the assumption of imperfect capital markets birdsall 1991 predicts greater expenditures on later born children as family income rises and older siblings become financially independent but the author also notes that firstborns do not initially have to compete for their parents time and attention in a frequently cited piece in the psychology literature zajonc 1976 likewise emphasizes the early period in a firstborn s cognitive development when parental attention is undivided 3 in fact most researchers working on birth order issues have assumed that children are particularly sensitive to parental time investments and the home environment at young ages 4 however certain nonmonetary parental inputs such as monitoring and supervision may become increasingly important as a child matures especially in the determination of risky or delinquent behaviors

an inventory system with two supply modes and capacity constraints abstract this paper analyses a periodic review inventory system with a main and an emergency supply mode where policies of the base stock type are used at both supply channels contrary to previously published models the capacity of the emergency channel is taken into account we examine two alternative ordering policies for that channel an early ordering policy that almost eliminates early stockouts in a replenishment cycle and a late ordering policy that delays the emergency order decision until more demand information has been accumulated approximate cost models are developed and properties of their optimal solutions are derived simulation results indicate that these solutions are near optimal conclusions are drawn about the relative effectiveness of the two emergency ordering policies

the effect of sibling sex composition on women s education and earnings this paper documents the impact of siblings on the education of men and women born in the united states between 1920 and 1965 we examine the effect of the number and sex composition of a boy or girl s siblings on that child s educational attainment we find that throughout the century women s educational choices have been systematically affected by the sex composition of her siblings and that men s choices have not women raised only with brothers have received on average significantly more education than women raised with any sisters controlling for household size since sibling sex composition affects women s educational attainment and plausibly may be unrelated to other determinants of earnings it may provide a useful instrument for education in earnings functions for women our results suggest that standard estimates significantly underestimate the return to schooling for women

food for thought the birth order effect and resource allocation in indonesia abstractdespite the large literature linking birth order to socio economic outcomes research uncovering the mechanisms that drive these effects has been rare we construct a unique measure of nutritional variety to examine whether differential resource allocation among siblings explains the birth order effect on cognitive ability we document birth order differences among children and young adults showing that second and third borns perform worse on cognitive assessments compared to their firstborn siblings we find further evidence suggesting that second and third born children frequently eat a smaller variety of food than their first born counterparts however this differentiation in food allocation does not appear to drive the differences in cognitive ability in our sample to our knowledge this article is the first both to confirm the presence of a birth order effect on cognition in a developing country and to test empirically whether a difference in food allocation contributes to this effect

a periodic review inventory model with two delivery modes fractional lead times and age and period dependent backlogging costs abstract we examine a periodic review inventory model where the buyer has access to a mix of two delivery modes for the quantity it orders in a period these include an emergency delivery mode that delivers instantaneously and a regular delivery mode that delivers within the length of the review period the unmet demand is backordered and charged a backlogging cost that varies with the length of the backlogging time the excess inventory is charged a holding cost the unit costs for the delivery modes could be different we show that the well known base stock policy structure remains optimal for this problem under mild conditions

a periodic review inventory system with emergency replenishments this paper proposes and analyzes a periodic review inventory system with two replenishment modes regular orders are placed periodically following a base stock policy on inventory position and arrive at the stocking location after a deterministic lead time the location also has the option of placing emergency orders characterized by a shorter lead time but higher acquisition cost in case of imminent stockouts thus at some appropriate time in the replenishment cycle the necessity and size of an emergency order is determined according to a base stock policy on net stock the timing of the emergency order is such that this order arrives and can be used to satisfy the demand in the time period just before the arrival of a regular order when the likelihood of a stockout is highest an approximate cost model is developed which can easily be optimized with respect to the order up to parameters this model is used as the basis for a heuristic algorithm which leads to solutions that are very close to the exact optimal solutions determined through simulation it is shown that the proposed system offers substantial cost savings relative to a system without the emergency replenishment option

new policies for the stochastic inventory control problem with two supply sources we study an inventory system under periodic review in the presence of two suppliers or delivery modes the emergency supplier has a shorter lead time than the regular supplier but the unit price he offers is higher excess demand is backlogged we generalize the recently studied class of dual index policies veeraraghavan s a scheller wolf 2008 now or later dual index policies for capacitated dual sourcing systems oper res 56 4 850 864 by proposing two classes of policies the first class consists of policies that have an order up to structure for the emergency supplier we provide analytical results that are useful for determining optimal or near optimal policies within this class this analysis and the policies we propose leverage our observation that the classical lost sales inventory problem is a special case of this problem the second class consists of policies that have an order up to structure for the regular supplier here we derive bounds on the optimal order quantity from the emergency supplier in any period and use these bounds for finding effective policies within this class finally we undertake an elaborate computational investigation to compare the performance of the policies we propose with that of dual index policies one of our policies provides an average cost saving of 1 1 over the best dual index policy and has the same computational requirements another policy that we propose has a cost performance similar to the best dual index policy but its computational requirements are lower

a fresh look at the rotten kid theorem and other household mysteries gary becker s rotten kid theorem asserts that if all family members receive gifts of money income from a benevolent household member then even if the household head does not precommit to an incentive plan for family members it will be in the interest of selfish family members to maximize total family income i show by examples that the rotten kid theorem is not true without assuming transferable utility i find a simple condition on utility functions that is necessary and sufficient for there to be the kind of transferable utility needed for a rotten kid theorem while restrictive these conditions still allow one to apply the strong conclusions of the rotten kid theorem in an interesting class of examples

the effect of a first child on female labor supply evidence from women seeking fertility services estimating the causal effect of a first child on female labor supply is complicated by the endogeneity of fertility this paper addresses this problem by focusing on a sample of women from the national survey of family growth nsfg who sought help to become pregnant after a certain period only some of these women gave birth results using this strategy show that having a first child younger than one year old reduces female employment by 26 percentage points these estimates are close to ols estimates from census data and to those from ols and fixed effects models on nsfg data

a production inventory system with markovian capacity and outsourcing option we study the optimal production inventory outsourcing policy for a firm with markovian in house production capacity that faces independent stochastic demand and has the option to outsource we find very simple optimal policy forms under fairly reasonable assumptions in addition when the capacity markov process is stochastically monotone the policy parameters decrease in the firm s current capacity level under additional assumptions all these results extend to the infinite horizon and undiscounted cost cases we analyze comparative statics and the necessity of some technical conditions and discuss when the outsourcing option is more valuable

a continuous review inventory model with order expediting abstract in this paper we consider a continuous review inventory system in which the lead time l includes a part of fixed duration t and a part whose duration can be either t a or t e where t a t e when the net inventory reaches the reorder point r an order of size q is released if the net inventory at time t after the order release is equal to or smaller than r e the order is expedited at a cost comprising a fixed cost and a cost per unit and the lead time is l t t e otherwise the lead time is l t t a therefore the decision variables considered are the order quantity q the reorder point r and the order expediting point r e our aim is to find the inventory policy variables q r and r e that minimize the average cost rate we present an algorithm to obtain the policy variables with global minimal costs when the inventory policy decision variables are integers we also discuss the case in which the decision variables are real valued

global dual sourcing and order smoothing the impact of capacity and lead times after decades of offshoring production across the world companies are rethinking their global networks local sourcing is receiving more attention but it remains challenging to balance the offshore sourcing cost advantage against the increased inventories because of its longer lead time and against the cost and volume flexibility of each source s capacity to guide strategic allocation in this global network decision this paper establishes reasonably simple prescriptions that capture the key drivers we adopt a conventional discrete time inventory model with a linear control rule that smoothes orders and allows an exact and analytically tractable analysis of single and dual sourcing policies under normal demand distinguishing features of our model are that it captures each source s lead time capacity cost and flexibility to work overtime we use lagrange s inversion theorem to provide exact and simple square root bound formulae for the strategic sourcing allocations and the value of dual sourcing the formulae provide structural insight on the impact of financial operational and demand parameters and a starting point for quantitative decision making we investigate the robustness of our results by comparing the smoothing policy with existing single and dual sourcing models in a simulation study that relaxes model assumptions this paper was accepted by yossi aviv operations management

multiechelon procurement and distribution policies for traded commodities we consider a firm that procures and distributes a commodity from spot and forward markets under randomly fluctuating prices the commodity is distributed downstream to a set of nonhomogeneous retailers to satisfy random demand we formulate a model that allows one to compute approximate but near optimal procurement and distribution policies for this system and we explore the value of the commodity s market in providing managers with a additional flexibility in procurement and b information on price dynamics generated through the trading of futures contracts our results indicate that the presence of the commodity market and the information that it conveys may lead to significant reductions in inventory related costs however to obtain these benefits both the spot procurement flexibility and the term structure of prices generated by the commodity market must be incorporated in the formulation of the operating policy managerial insights on the procurement strategy as a function of variability in prices and demand are also discussed this paper was accepted by john birge focused issue editor

children and their parents labor supply evidence from exogenous variation in family size although theoretical models of labor supply and the family are well developed there are few credible estimates of key empirical relationships in the work family nexus this study uses a new instrumental variable the sex composition of the first two births in families with at least two children to estimate the effect of additional children on parents labor supply in the united states instrumental variables estimates using the sex mix are substantial but smaller than the corresponding ordinary least squares ols estimates moreover unlike the ols estimates the female labor supply effects estimated using sex mix instruments appear to be absent among more educated women and women with high wage husbands we also find that married women who have a third child reduce their labor supply by as much as women in the full sample while there is no relationship between wives child bearing and husbands labor supply excerpt

the more the merrier the effect of family size and birth order on children s education there is an extensive theoretical literature that postulates a tradeoff between child quantity and quality within a family however there is little causal evidence that speaks to this theory using a rich dataset on the entire population of norway over an extended period of time we examine the effects of family size and birth order on the educational attainment of children while we find a negative correlation between family size and children s education when we include indicators for birth order and or use twin births as an instrument family size effects become negligible in addition birth order has a significant and large negative effect on children s education we also study adult earnings employment and teenage childbearing and find strong evidence for birth order effects with these outcomes particularly among women these findings suggest the need to revisit economic models of fertility and child production focusing not only on differences across families but differences within families as well

a continuous review model for an inventory system with two supply modes in this paper we develop an approximate model of an inventory control system in which there exist two options for resupply with one having a shorter lead time because the optimal policy appears to be extremely complex we consider a reasonable extension of the standard q r policy to allow for two different lot sizes q1 and q2 and two different reorder levels r1 and r2 expressions for the expected on hand inventory and the expected backorders are developed and a procedure for determining the policy parameters is given the model is validated by simulation and calculations are included which compare the average annual cost with and without emergency ordering

sibling gender and wage differences abstractfamily influences on economic performance are investigated in particular sibship sex composition is related to hourly wages using data from the national longitudinal survey of youth 1979 the wages of men are increasing in the proportion of siblings who are brothers but the wages of women are insensitive to sibling gender nonwage outcomes are generally unaffected contrasts by age structure and demographic group are also presented the analysis addresses econometric challenges like the endogeneity of fertility and selection into the workforce in addition mechanisms such as labour market interactions human capital investment and role model effects are documented a questionnaire on job search indicates a same gender bias in the use of brothers and sisters in obtaining employment developmental and psychological assessments suggest that brothers may be associated with worse childhood home environments and more traditional family attitudes among women the findings are policy relevant and cont

inventory control with generalized expediting we consider a single item periodic review inventory control problem in which discrete stochastic demand must be satisfied when shortages occur the unmet demand must be filled by some form of expediting we allow a very general form for the cost structure of expediting we explicitly consider the case where expedited production is allowed to produce up to a positive inventory level we also consider the case where expedited production beyond the deficit is not permitted an alternate application for this model is an inventory system with general lost sales costs for the infinite horizon discounted problem we characterize the structure of the optimal stationary expediting policy and show that an s s policy is optimal for regular production for the special cases where the expediting cost function is concave or consists of a fixed and linear per unit cost we show that the optimal stationary expediting policy is generalized s s or order up to respectively a numerical study allows us to gain insight into when expediting above and beyond the deficit is cost effective

child care subsidies and labor supply in sweden this paper utilizes data from a swedish household survey for 1984 the hus data in combination with data on public child care fees and spaces per child by community we argue that the subsidy rate and availability of spaces determined by the political leaders of the community is to a large extent exogenous to the household the joint out of home child care and labor supply decision is analyzed by logit and ordered probit choice models we find that the high quality public child care in sweden encourages labor market activity of women with preschoolers even when the spouse s income is high and that when spaces are not rationed a lower price encourages use

the trade off between child quantity and quality an empirical investigation of trade offs between number of children and their scholastic performance confirms that family size directly affects children s achievement though parents show no favori

leadtime management in a periodic review inventory system a state dependent base stock policy we examine a single item periodic review inventory system with stochastic leadtimes in which a replenishment order is delivered immediately or one period later depending probabilistically on costly effort the objective is to determine a joint inventory policy and effort choice strategy that minimizes the expected total costs our analytical and computational analysis suggests that i a state dependent base stock policy is optimal ii the optimal effort strategy is such that the marginal cost of effort is equal to the value of immediate delivery and iii the cost impact of leadtime reduction can be very large we also provide some counter intuitive results compared with the traditional multi period newsvendor model