consumption and children abstract consumption by couples rises sharply in the beginning and falls later in life the causes of the early rise are hotly contested among the suggestions are rule of thumb behavior demographics liquidity constraints the precautionary motive and nonseparabilities between consumption and labor supply we develop two tests of the extreme hypothesis that only changes in family structure matter we estimate effects of the numbers and ages of children on consumption these estimates allow us to rationalize all of the increase in consumption without recourse to any of the causal mechanisms our estimates can be interpreted either as giving upper bounds on the effects of children or as evidence that the other causes are not important

fertility risk in the life cycle in this paper i study fertility decisions of women in the u s economy with special emphasis on the timing of births and abortions over the life cycle given the policy debate regarding abortion availability along with empirical evidence on its positive impact on women outcomes understanding the fertility process in a broad sense should help guide the discussion in this paper i present a life cycle model of consumption savings and fertility decisions in an environment with uninsurable income shocks and imperfect fertility control my model presents a unified framework in which opportunity costs of child rearing as well as technological restrictions in the form of contraception effectiveness have roles to understand lifetime fertility the model extends important earlier work on contraceptive decisions by women in the sense that it allows for stochastic fertility outcomes and is able to account for the interplay between asset accumulation and fertility decisions observed in the data

rational household labor supply traditionally household behavior is derived from the maximization of a unique utility function in this paper we propose an alternative approach in which the household is modeled as a two member collectivity taking pareto efficient decisions the consequences of this assumption are analyzed in a three good model in which only total consumption and each member s labor supply are observable if the agents are assumed egoistic i e they are only concerned with their own leisure and consumption it is possible to derive falsifiable conditions upon household labor supplies from both a parametric and nonparametric viewpoint if alternatively agents are altruistic restrictions obtain in the nonparametric context useful interpretation stems from the comparison with the characterization of aggregate demand for a private good economy

an empirical analysis of life cycle fertility and female labor supply this paper examines us household fertility and female labor supply over the life cycle using data from the panel study of income dynamics the authors investigate how maternal time inputs and market expenditures on offspring as well as the benefits they yield their parents vary with ages of offspring and influence female labor supply and contraceptive behavior the econometric framework combines a female labor supply model and a contraceptive choice index function it also accounts for the fact that conceptions are not perfectly controllable events using longitudinal data on married couples the authors estimate these equations and test alternative specifications of the technologies governing child care the findings suggest that while parents cannot perfectly control conceptions variations in child care costs do affect life cycle spacing of births furthermore the results demonstrate the gains of modeling the linkages between female labor supply and fertility behavior at the household level authors modified

intra household allocation of time and money across siblings abstract how work and consumption are allocated within the family has important consequences for the welfare of individual household members using data on time use and assignable goods for individual siblings across india peru ethiopia and vietnam aged 5 17 i show that there is substantial within sibling variation in leisure as well as consumption allocations i then test whether there is evidence for favoritism in the joint allocation of leisure and consumption toward a particular gender i find that boys with a younger sister have substantially more relative leisure compared to girls with a younger sister in all four countries consumption allocations are relatively higher for older siblings of mixed gender sibling pairs irrespective of the sex of the child i reject that favoritism in consumption equals favoritism in leisure in three of the four countries finally i show suggestive evidence on the role of reward and preferences for allocations of time and money in the household

the gender gap fertility and growth changes in fertility have long been recognized as important correlates of economic growth with the relationship between the level of fertility and the level of income per capita being one of the strongest observable correlations in cross country data this paper examines the linkages between fertility and growth theory the structure of the model is presented in sections on production couples decision making system dynamics and steady state equilibria the first component of the model is that increases in capital per worker raise womens relative wages since capital is more complementary to womens labor input than to mens the second component is that increasing womens relative wages reduces fertility by raising the cost of children more than household income finally lower fertility raises the level of capital per worker a positive feedback loop generates demographic transition a rapid decline in fertility accompanied by accelerated output growth

family planning in a life cycle model with income risk several us states have recently restricted the access to abortions we study fertility intentions and how family planning and abortions are used as mechanisms to control fertility among couples facing income risk we formulate and estimate a life cycle consumption saving model with uninsurable income risk and imperfect contraceptive control that matches fertility behavior in the british household panel survey bhps well we use the estimated model to investigate how family planning and abortions are used to control fertility in our model our simulations suggest that income risk affects family planning and that abortion is used to control fertility due to the presence of income risk this indicates that the availability of abortions might play a role as an insurance mechanism

wealth accumulation over the life cycle and precautionary savings this article constructs and simulates a life cycle model of wealth accumulation and estimates the parameters of the utility function the rate of time preference and the coefficient of risk aversion by matching the simulated median wealth profiles with those observed in the panel study of income dynamics and in the survey of consumer finances the estimates imply a low degree of patience and a high degree of risk aversion the results are used to study the importance of precautionary savings in explaining wealth accumulation they imply that wealth accumulation is driven mostly by precautionary motives at the beginning of the life cycle whereas savings for retirement purposes become significant only closer to retirement

optimal aging and death understanding the preston curve does prosperity lead to greater longevity if so what is the strength of the income channel to address these questions we develop a life cycle model in which households are subject to physiological aging in modeling aging we draw on recent research in the elds of biology and medicine the speed of the aging process and thus the time of death are endogenously determined by optimal health investments a calibrated version of the model accounts well for the observed non linear cross country link between longevity and income also known as the preston curve

preference heterogeneity in experiments comparing the field and laboratory do laboratory experiments provide a reliable basis for measuring field preferences economists recognize that preferences can differ across individuals but only a few attempts have been made to elicit individual preferences for representative samples of a population in a particular geographical area region or country our primary objective is to directly compare estimates of preferences elicited from a convenience sample and the estimates for the wider population from which that sample is drawn we examine the strengths and weaknesses of laboratory and field experiments to detect differences in preferences over risk and time that are associated with standard observable characteristics of the individual

non cooperative bargaining of n 3 players abstract extensions to n 3 players of rubenstein s 1982 bargaining model with fixed common discount factor are considered if voting takes place simultaneously then any partition of the cake is a subgame perfect nash equilibrium outcome

estimating intertemporal allocation parameters using synthetic residual estimation we present a novel structural estimation procedure for models of intertemporal allocation this is based on modelling expectations errors directly we refer to it as synthetic residual estimation sre the flexibility of sre allows us to account for measurement error in consumption and for heterogeneity in intertemporal allocation parameters an investigation of the small sample properties of the sre estimator indicates that it dominates generalized method of moments gmm estimation of both exact and approximate euler equations in the case when we have short panels and noisy consumption data we apply sre to two panels drawn from the panel study of income dynamics psid and estimate the joint distribution of the discount factor and the elasticity of intertemporal substitution we reject strongly homogeneity of the discount factor and the elasticity of intertemporal substitution we find that on average the more educated are more patient and less willing to substitute intertemporally than the less educated within education strata patience and willingness to substitute are positively correlated 2010 the review of economic studies limited

teen motherhood and abortion access it is argued that the net effect of any restriction of abortion access on birth rates is an empirical question this study examines the impact of access to abortion on county teenage birth rates birth rates are expected to decrease by 1 among white adolescents aged 15 19 years for a 25 mile increase in the distance to the nearest abortion provider particularly among in wedlock births data are obtained from 1973 88 national natality local area summary files for counties in the us and four other national sources data did not provide useful information on the empirical relationship between access and birth rate for densely populated urban areas cross sectional findings that had omitted variable bias indicate that an increase of 25 miles in distance to a provider was associated with an additional 1 4 births per 1000 white teenage women or a 3 increase in the average teen birth rate of 45 1000 white teenagers the findings from a county fixed effects model that controlled for omitted variable bias indicate that an increase of 25 miles was associated with a reduction in teen births of 0 5 1000 or about 1 of the mean birth rate both medicaid restrictions and parental consent laws were negative and significant and more negative in poor and more isolated counties the state year effects models did not change findings on distance and medicaid restriction effects the effects of changes in timing of laws suggests that laws followed preexisting trends changes in distance to provider were primarily in the first 2 years following the change out of wedlock births were unaffected by changes in distance to providers the out of wedlock teen birth rate increased with a complete ban on abortions fewer wanted births were associated with small restrictions findings imply that closing of clinics during 1977 88 had an impact on teen birth rates of under one tenth of 1 the 20 increase in teen births was unexplained

survey measures of risk aversion and prudence this paper utilizes a thought experiment conducted by the bank of italy to estimate absolute and relative risk aversion along with absolute and relative prudence for a broad cross section of italian households upper and lower bounds are calculated for each parameter and comparisons are made across socio demographic groups evidence is found of decreasing absolute risk aversion decreasing absolute prudence increasing relative risk aversion and increasing relative prudence

the career costs of children this paper analyzes the life cycle career costs associated with child rearing and decomposes their eects into unearned wages as women drop out of the labor market loss of human capital and selection into more child friendly occupations we estimate a dynamic life cycle model of fertility occupational choice and labor supply using detailed survey and administrative data for germany for numerous birth cohorts across dierent regions we use this model to analyze both the male female wage gap as it evolves from labor market entry onward and the eect of pro fertility policies we show that a substantial portion of the gender wage gap is explainable by realized and expected fertility and that the long run eect of policies encouraging fertility are considerably lower than the short run eects typically estimated in the literature

habit persistence and teen sex could increased access to contraception have unintended consequences for teen pregnancies we develop a dynamic discrete choice model of teen sex and pregnancy that incorporates habit persistence habit persistence has two sources here the first is a fixed cost of having sex which relates to a moral or psychological barrier that has been crossed the first time one has sex the second is a transition cost whereby once a particular relationship has progressed to sex it is difficult to move back we estimate significant habit persistence in teen sex implying that the long run effects of contraception policy may be different from their short run counterparts especially if the failure rate of contraception is sufficiently large programs that increase access to contraception are found to decrease teen pregnancies in the short run but increase them in the long run

evaluating echelon stock r nq policies in serial production inventory systems with stochastic demand this paper studies echelon stock r nq policies in serial production inventory systems with stochastic demand we provide a recursive procedure to compute the steady state echelon inventory levels of the systems which can be used to evaluate the long run average holding and backorder costs as well as other performance measures the procedure is based upon an observation of a relationship between the inventory status of adjacent stages in a serial system we also device exact formulas for replenishment frequencies and setup costs our results apply to both continuous review systems with compound poisson demand and periodic review systems with independent identically distributed demands a preliminary numerical study was conducted to explore the cost effectiveness of echelon stock r nq policies for two stage systems with simple poisson demand we compared among the minimum costs of echelon stock r nq policies a lower bound on the minimum achievable costs and the minimum costs of installation stock r nq policies finally we present a modification of an existing approximate evaluation procedure

exact evaluation of batch ordering inventory policies in two echelon supply chains with periodic review this paper studies a two echelon supply chain with stochastic and discrete consumer demand batch order quantities periodic inventory review and deterministic transportation times reorder point policies manage inventories at every location average inventory backorders and fill rates are evaluated exactly for each location safety stock is evaluated exactly at the lower echelon and a good approximation is detailed for the upper echelon numerical data are presented to demonstrate the model s utility it is found that system costs generally increase substantially if the upper echelon is restricted to carry no inventory of if the upper echelon is required to provide a high fill rate in many cases it is optimal to set the upper echelon s reorder point to yield near zero safety stock yet in some cases this simple heuristic can significantly increase supply chain operating costs finally policies selected under the assumption of continuous inventory review can perform poorly if implemented in an environment with periodic review

negligible senescence an economic life cycle model for the future abstract we propose a model of aging and health deficit accumulation model with an infinite time horizon and a steady state of constant health the time of death is uncertain and endogenous to lifestyle and health behavior this setup can be conceptualized as a strive for immortality that is never reached we discuss adjustment dynamics and show that the new setup is particularly useful to understand aging of the oldest old i e of individuals for which morbidity and mortality have reached a plateau we then show how the existence of a steady state can be used to perform comparative dynamics exercises analytically as an illustration we investigate the effects of more expensive health investment and of advances in medical technology on optimal short run and long run health behavior

risk aversion and incentive effects new data without order effects holt and laury 2002 used a menu of ordered lottery choices to make inferences about risk aversion under various payment conditions the main results of that paper were a subjects are risk averse even for relatively small payments of less than 5 b risk aversion increases sharply with large increases in the scale of cash payoffs and c there is no significant effect from increasing the scale of hypothetical payment with a few exceptions noted in the paper all treatments began with a low payment choice followed by a choice with hypothetical payments that had been scaled up by 20 50 or 90 followed by a real cash decision with the same high payment scale 20 50 or 90 followed by a single final low 1 real payment choice those in the 90 treatment could earn amounts ranging from 9 00 to 346 50 in this task as glenn w harrison et al 2004 correctly note this design confounds order and treatment effects since the high real payment choice was always completed after the low real and high hypothetical payment tasks in a new experiment reported below we first seek to replicate harrison et al s finding that the order effect participating in a low payment choice before making a high payment choice magnifies the scale effect in a second treatment each subject completes the menu of lottery choices under just one payment condition 1 or 20 real or hypothetical thereby eliminating any order effects i new data

simple solutions to the initial conditions problem in dynamic nonlinear panel data models with unobserved heterogeneity i study a simple widely applicable approach to handling the initial conditions problem in dynamic nonlinear unobserved effects models rather than attempting to obtain the joint distribution of all outcomes of the endogenous variables i propose finding the distribution conditional on the initial value and the observed history of strictly exogenous explanatory variables the approach is flexible and results in simple estimation strategies for at least three leading dynamic nonlinear models probit tobit and poisson regression i treat the general problem of estimating average partial effects and show that simple estimators exist for important special cases copyright 2005 john wiley sons ltd

a robustness study of a multi echelon inventory model via simulation abstract this paper examines the robustness of a standard model of multi echelon inventory systems specifically the models discussed in axsater oper res 48 5 2000 686 a simulation model was developed to explore the model s ability to predict system performance for a two echelon one warehouse multiple retailer system using r q inventory policies under conditions that violate the model s fundamental modeling assumptions in particular the impact of non stationary demand on this stationary demand inventory model was examined the model performs well at the low demand and large retailer order batch size situations but our testing of the model indicated that care must be taken when applying this model to situations that violate its fundamental assumption these results should help practitioners to better understand the assumptions of these models and to determine when or when not to apply these models in practice

multi level inventory systems with stochastic demand when products are distributed over a large region it is common to have several local stocking locations close to the final customers these local inventories are in turn customers of a higher level stocking site for example a central warehouse the resulting inventory system see figure 1 is denoted a distribution system or an arborescent system open image in new window figure 1 two level distribution system

fertility choice in a life cycle model with idiosyncratic uninsurable earnings risk abstract motivated by large shifts in uninsurable earnings risk over time this paper studies the link between delaying and reducing fertility on the one hand and earnings and fertility risks on the other when children are modeled as consumption commitments increases in earnings risk are associated with a reduction in family sizes and patterns of delayed childbearing since household ability to bear children declines with age the postponement of birth associated with the increased earnings risk drives down the number of birth per family further an access to in vitro fertilization ivf is shown to have only a limited offsetting effect

stock wars inventory competition in a two echelon supply chain with multiple retailers this paper studies the competitive and cooperative selection of inventory policies in a two echelon supply chain with one supplier andn retailers stochastic demand is monitored continuously retailers incur inventory holding and backorder penalty costs the supplier incurs holding costs for its inventory and backorder penalty costs for backorders at the retailers the latter cost reflects the supplier s desire to maintain adequate availability of its product to consumers previous research finds the supply chain cost minimizing reorder point policies the cooperative solution the competitive solution is a nash equilibrium a set of reorder points such that no firm can deviate from the equilibrium and lower its cost it is shown that nash equilibria exist and a method is presented to find all of them in some settings the cooperative solution is a nash equilibrium competition does not necessarily lead to supply chain inefficiency in other settings competition leads to costs that are substantially higher than optimal usually but not always the competitive supply chain carries too little inventory three cooperation strategies are discussed change incentives change equilibrium and change control a set of contracts is provided that changes the firms incentives so that the optimal policy is a nash equilibrium an equilibrium change can improve performance but does not guarantee optimal performance to change control the firms let the supplier choose all reorder points a key component in vendor managed inventory that change leads to optimal supply chain performance

luxuries are easier to postpone a proof we show that marshallian income elasticities are proportional to frisch own price elasticities if all goods are additively separable this implies that luxuries are likely to be easier to postpone it also implies that preferences over consumption are unlikely to display a constant elasticity of substitution

the demographic transition and the sexual division of labor this paper presents a theory in which increases in female labor force participation and reductions in the gender wage gap are generated as part of a single process of demographic transition initially characterized by reductions in mortality and fertility the paper suggests a relationship between gains in life expectancy and changes in the role of women in society that has not been identified before in the literature mortality reductions affect the incentives of individuals to invest in human capital and to have children with implications for female labor force participation and the wage differential between men and women the paper also presents some empirical evidence to support the predictions of the theory

health insurance and retirement of married couples summary most health insurance in the usa is provided by employers until eligibility for public health insurance medicare begins at age 65 retiring before 65 exposes workers who lack retiree health insurance coverage to the risk of catastrophic medical expenditure we solve and estimate a dynamic model of the employment behavior of older married couples that includes risky medical expenditure and health insurance parameter estimates imply that the risk reducing feature of health insurance can account for about half of the observed association between retiree health insurance and employment for married men but can account for only one tenth of the much larger observed association for married women policy simulations imply very small effects on employment of changing the age of eligibility for medicare from 65 to 67 copyright 2006 john wiley sons ltd

94 effective policies for a two stage serial inventory system with stochastic demand a two stage inventory system is considered where poisson demand occurs at stage 1 and stage 1 replenishes its inventory from stage 2 which in turn orders from an outside supplier with unlimited stock each shipment either to stage 2 or to stage 1 incurs a fixed setup cost under the assumption that the supply leadtime at stage 2 is zero we characterize a simple heuristic policy whose long run average cost is guaranteed to be within 6 of optimality i e a 94 effective policy the paper also provides heuristic policies for more general inventory systems and reports computational results

the baby boom and baby bust what caused the baby boom and can it be explained within the context of the secular decline in fertility that has occurred over the last 200 years the hypothesis is that a the secular decline in fertility is due to the relentless rise in real wages that increased the opportunity cost of having children b the baby boom is explained by an atypical burst of technological progress in the household sector that occurred in the middle of the last century this lowered the cost of having children a model is developed in an attempt to account quantitatively for both the baby boom and bust

the saving behaviour of a two person household the facts that wives are typically younger than their husbands and that women typically live longer than men imply that wives may have more incentive to save for old age than do husbands a theoretical model of the determination of household saving and portfolio choice is introduced which takes into account differences in preferences for saving the most important result is that the level and the composition portfolio of saving and the time path of consumption are dependent on the distribution of income within the household women typically live longer than men and wives are typically younger than their husbands these two facts imply that preferences about saving for old age in married households with forward looking members may differ between husband and wife this paper presents a theoretical analysis of saving and portfolio behaviour if the members of the household have differ ent preferences over future consumption as compared to current consump tion the analysis stands in contrast to unitary models of household intertemporal allocation which assume that the household has a single utility function thus this paper is a contribution in a novel context to the burgeoning literature on intra household decision making the base case analysis is for a simple two person husband and wife1 two period model in which there is only one asset saving it is assumed that because of the two facts given at the start of the introductory paragraph the husband discounts the future more than the wife in section ii the implications of a non cooperative decision making process for the base case are derived see ulph 1988 for a non cooperative model of demand and

the effects of marital status and children on savings and portfolio choice this paper investigates the impact of demographic shocks on optimal decisions about saving life insurance and most centrally asset allocation we analyze these choices within the framework of a life cycle model that features exogenous changes in family composition heterogeneity in lifetime income and uninsurable fluctuations in earnings and medical costs our analysis indicates that marital status transitions and children can have important effects on optimal household decisions widowhood induces sharp reductions in the portfolio shares in stock and the impact is largest for women and individuals with children divorce causes men and women to reallocate their portfolios in different directions men choose much riskier allocations while women opt for safer ones children play a fundamental role in the optimal portfolio decisions men with children for example increase their shares in response to divorce by less than half as much as men without children comparing our simulation results with panel data evidence on stockholding from the psid and the hrs we conclude that changes in marital status and children matter empirically as well but not always in the ways that the model predicts

life insurance and household consumption abstract using life insurance holdings by age sex and marital status we infer how individuals value consumption in different demographic stages we estimate equivalence scales and bequest motives simultaneously within a fully specified model where agents face us demographics and save and purchase life insurance our findings indicate that individuals are very caring for dependents that economies of scale are large that children are very costly or yield very high marginal utility that wives with children produce lots of home goods and that females display habits from marriage while men do not these findings contrast sharply with standard equivalence scales

coordination mechanisms of supply chain systems supply chain management scm has become an important management paradigm as supply chain members are often separate and independent economic entities a key issue in scm is to develop mechanisms that can align their objectives and coordinate their activities so as to optimize system performance in this paper we provide a review of coordination mechanisms of supply chain systems in a framework that is based on supply chain decision structure and nature of demand this framework highlights the behavioral aspects and information need in the coordination of a supply chain the identification of these issues points out several directions of future research in this area

measuring the sensitivity of parameter estimates to estimation moments we propose a local measure of the relationship between parameter estimates and the moments of the data they depend on our measure can be computed at negligible cost even for complex structural models we argue that reporting this measure can increase the transparency of structural estimates making it easier for readers to predict the way violations of identifying assumptions would affect the results when the key assumptions are orthogonality between error terms and excluded instruments we show that our measure provides a natural extension of the omitted variables bias formula for nonlinear models we illustrate with applications to published articles in several fields of economics

abortion legalization and child living circumstances who is the marginal child weexaminethe impact ofincreased abortion availabilityon the averageliving standards of children through a selection effect would the marginal child whowas not born have grown up in different circumstances than the average child we use variation in the timing of abortion legalization across states to answer this question cohorts born after legalized abortion experienced a signiecant reduction in a number of adverse outcomes we end that the marginal child would have been 40 60 percent more likely to live in a single parent family to live in poverty to receive welfare and to die as an infant access to abortion is one of the most contentious public policy issues facing the united states today the period since the legalization of abortion under the roe v wade decision of 1973 has been marked by incessant debate over the appropriate government enancing and legal status of abortions meanwhile pregnancy resolution through abortion is a very common outcome in the united states roughly 25 percent of all pregnancies are aborted ventura et al 1995 as a result major changes in abortion access could have substantial effects on the birthrate indeed levine staiger kane and zimmerman end that the legalization of abortion in the early 1970s led to an 8 percent reduction in the birthrate 1

multiperson bargaining over two alternatives abstract we present a continuous time model of multiperson bargaining with incomplete information where only two agreements are possible we show that under mild informational assumptions players behave as if they were representing the other players who prefer the same alternative individually playing a war of attrition against a conglomerate player of the opposite side we also provide a characterization of the perfect bayesian equilibria in undominated strategies of the game which yields a unique outcome in most cases journal of economic literatureclassification numbers c72 c78 d72 d74

more on marriage fertility and the distribution of income according to pareto 1896 the distribution of income depends on the nature of the people comprising a society on the organization of the latter and also in part on chance in the model developed here the nature of the people is captured by attitudes toward marriage divorce fertility and children singles search for mates in a marriage market married agents bargain about work and the quantity and quality of children they can divorce social policies such as child support requirements reflect the organization of the society finally chance is modeled by randomness in income marriage opportunities and marital bliss

an estimable dynamic stochastic model of fertility and child mortality this paper develops a finite horizon dynamic stochastic model of discrete choice with respect to life cycle fertility within an environment where infant survival is uncertain the model yields implications for the number timing and spacing of children a tractable estimation method is developed for the linear constraint quadratic utility case that is intimately tied to the dynamic optimization problem and the method is applied to malaysian household data estimation is based on integrating the numerical solution of the dynamic programming model of behavior with a maximum likelihood procedure

revisiting the effect of household size on consumption over the life cycle abstract although the link between household size and consumption has strong empirical support there is no consistent way in which demographics are dealt with in standard life cycle models we study the relationship between the predictions of the single agent model the standard in the literature versus a simple model extension the demographics model where deterministic changes in household size and composition affect optimal consumption decisions we show theoretically that the demographics model is conceptually preferable to the single agent model as it captures economic mechanisms ignored by the latter however our quantitative analysis demonstrates that differences in predictions for consumption are negligible across models when using standard calibration strategies this suggests that it is largely irrelevant which model specification is used

non cooperative bargaining theory an introduction the paper provides an informal introduction to some of the main themes of the recent literature on non cooperative or sequential bargaining models it focuses in particular on the relationship between the new approach and the traditional axiomatic approach exemplified by nash bargaining theory it illustrates the new insights offered by the non cooperative approach by reference to a detailed analysis of the manner in which the presence of an outside option available to one of the parties will affect the negotiated outcome finally the difficulties which arise in extending this analysis to two person bargaining with incomplete information and to n person bargaining are discussed this is a revised version of the fourth review of economic studies lecture presented in april 1985 at the joint meeting of the association of university teachers of economics and the royal economic society held in oxford the choice of lecturer is made by a panel whose members are currently professors hahn mirrlees and nobay and the paper is refereed in the usual way this paper aims to provide an informal and elementary introduction to an approach to bargaining which has received a great deal of attention over the past few years the approach involves writing down some particular sequence of moves offers and replies to be made over time in the course of negotiations and then looking for a non cooperative equilibrium in the game thus specified in practice a perfect equilibrium or in games of incomplete information a sequential equilibrium while the approach appears at first sight to be very different in spirit from the traditional axiomatic approach in which a bargaining solution is specified by appealing to a number of general requirements which are deemed appropriate on the basis of some a priori considerations the two approaches are in fact complementary while the

batch size and stocking levels in multi echelon repairable systems in multi echelon repairable inventory systems with high set up cost for order and or high demand rates the use of batch ordering may be more cost effective than the common s 1 s ordering policy this paper addresses the issue of determining the optimal order batch size and stocking levels at the stocking locations in such a system a power approximation is used to estimate the total system stock and backorder levels from which the optimal batch size can be readily determined a search routine involving one pass searches are then followed to obtain the stocking levels at the depot and the local sites of the system this procedure has been evaluated using 900 test cases and has been found to be very effective the power approximation approach also results in a simple analytical relationship to test whether or not s 1 s is an optimal ordering policy for repairable items in a multi echelon environment

housing decision with divorce risk we build a realistically calibrated life cycle model of housing decisions under divorce risk as observed in the data our model predicts the recent increase in divorce rates leads to reduced homeownership rates the event of a divorce negatively affects homeownership and this effect is long lasting the risk of a divorce triggers a precautionary savings motive however this motive is weaker when individuals can invest in owner occupied homes because homeowners higher savings partially substitute for precautionary savings when young the larger asset accumulation due to divorce risk induced precautionary savings enables households to buy homes earlier whereas the presence of transaction costs leads to reduced homeownership for middle aged and older households when divorce risk goes up

the gender gap in mortality how much is explained by behavior abstract in developed countries women are expected to live about 4 5 years longer than men in this paper we develop a novel approach to gauge the extent to which gender differences in longevity can be attributed to gender specific preferences and health behavior we set up a physiologically founded model of health deficit accumulation and calibrate it using recent insights from gerontology from fitting life cycle health expenditure and life expectancy we obtain estimates of the gender specific preference parameters we then perform the counterfactual experiment of endowing women with the preferences of men in our benchmark scenario this reduces the gender gap in life expectancy from 4 6 to 1 4 years when we add gender specific preferences for unhealthy consumption the model can motivate up to 89 percent of the gender gap our theory offers also an economic explanation for why the gender gap declines with rising income

optimization of order up to s policies for two level inventory systems with compound poisson demand abstract we consider a two level inventory system with one warehouse and n retailers leadtimes are constant and the retailers face different compound poisson demand processes all facilities apply order up to s replenishment policies we show how to evaluate holding and shortage costs exactly

on the benefits of delayed ordering practical experience and scientific research show that there is scope for improving the performance of inventory control systems by delaying a replenishment order that is otherwise triggered by generalised and all too often inappropriate assumptions this paper presents the first analysis of the most commonly used continuous s s policies with delayed ordering for inventory systems with compound demand we analyse policies with a constant delay for all orders as well as more flexible policies where the delay depends on the order size for both classes of policies and general demand processes we derive optimality conditions for the corresponding delays in a numerical study with erlang distributed customer inter arrival times we compare the cost performance of the optimal policies with no delay a constant delay and flexible delays sensitivity results provide insights into when the benefit of delaying orders is most pronounced and when applying flexible delays is essential

the effects of health insurance and self insurance on retirement behavior this paper provides an empirical analysis of the effects of employer provided health insurance medicare and social security on retirement behavior using data from the health and retirement study we estimate a dynamic programming model of retirement that accounts for both saving and uncertain medical expenses our results suggest that medicare is important for understanding retirement behavior and that uncertainty and saving are both important for understanding the labor supply responses to medicare half the value placed by a typical worker on his employer provided health insurance is the value of reduced medical expense risk raising the medicare eligibility age from 65 to 67 leads individuals to work an additional 0 074 years over ages 60 69 in comparison eliminating 2 years worth of social security benefits increases years of work by 0 076 years

how does future income affect current consumption this paper tests a straightforward implication of the basic life cycle model of consumption that current consumption depends on expected lifetime income the paper projects future income for a panel of households and finds that consumption is closely related to projected current income but unrelated to predictable changes in income however future income uncertainty has an important effect consumers facing greater income uncertainty consume less the results are consistent with buffer stock models of consumption like those of deaton 1991 or carroll 1992a 1992b where precautionary motives greatly reduce the willingness of prudent consumers to consume out of uncertain future income

an analysis of out of wedlock childbearing in the united states this paper relates the erosion of the custom of shotgun marriage to the legalization of abortion and the increased availability of contraception to unmarried women in the united states the decline in shotgun marriage accounts for a significant fraction of the increase in out of wedlock first births several models illustrate the analogy between women who do not adopt either birth control or abortion and the hand loom weavers both victims of changing technology mechanisms causing female immiseration are modeled and historically described this technology shock hypothesis is an alternative to welfare and job shortage theories of the feminization of poverty excerpt

collective labor supply and welfare the paper develops a general collective model of household labor supply in which agents are characterized by their own possibly altruistic preferences and household decisions are only assumed to be pareto efficient an alternative interpretation is that there are two stages in the internal decision process agents first share nonlabor income according to some given sharing rule then each one optimally chooses his or her own labor supply and consumption this setting is shown to generate testable restrictions on labor supplies moreover the observation of labor supply behavior is sufficient for recovering individual preferences and the sharing rule up to a constant finally the traditional tools of welfare analysis can be adapted to the new setting

income and consumption a micro semistructural analysis with pervasive heterogeneity we develop a model of consumption and income that allows for pervasive heterogeneity in the parameters of both processes introducing codependence between household income parameters and preference

modified echelon r q policies with guaranteed performance bounds for stochastic serial inventory systems we consider the classic continuous review nstage serial inventory system with a homogeneous poisson demand arrival process at the most downstream stage stage 1 any shipment to each stage regardless of its size incurs a positive fixed setup cost and takes a positive constant lead time the optimal policy for this system under the long run average cost criterion is unknown finding a good worst case performance guarantee remains an open problem we tackle this problem by introducing a class of modified echelon r q policies that do not require qi 1 qi to be a positive integer stage i 1 ships to stage i based on its observation of the echelon inventory position at stage i if it is at or below ri and stage i 1 has positive on hand inventory then a shipment is sent to stage i to raise its echelon inventory position to ri qias close as possible we construct a heuristic policy within this class of policies which has the following features first it has provably primitive dependent performance bounds in a two stage system the performance of the heuristic policy is guaranteed to be within 1 k1 k2 times the optimal cost where k1 is the downstream fixed cost and k2 is the upstream fixed cost we also provide an alternative performance bound which depends on efficiently computable optimal r q solutions to n single stage systems but tends to be tighter second the heuristic is simple it is efficiently computable and it performs well numerically it is even likely to outperform the optimal integer ratio echelon r q policies when k1 is dominated by k2 third the heuristic is asymptotically optimal when we take some dominant relationships between the setup or holding cost primitives at an upstream stage and its immediate downstream stage to the extreme for example when h2 h1 0 where h1 is the downstream holding cost parameter and h2 is the upstream holding cost parameter

spending on children direct survey evidence we present estimates of spending on children from a danish expenditure survey which asks respondents directly about allocations of expenditures to individual household members our main finding is that the average danish family allocates 44 of total assignable spending on non food non durables and services to children there is considerable variation across households more is spent on older children and expenditure on children is an increasing concave function of the number of equivalent children we find that households in which the mother has had a child by a previous partner spend 24 less on children than otherwise similar households

consumption and labor supply with partial insurance an analytical framework we develop a model with partial insurance against idiosyncratic wage shocks to quantify risk sharing closed form solutions are obtained for equilibrium allocations and for moments of the joint distribution of consumption hours and wages we prove identification and demonstrate how labor supply data are informative about risk sharing the model estimated with us data over the period 1967 2006 implies that i 39 percent of permanent wage shocks pass through to consumption ii the share of wage risk insured increased until the early 1980s and iii preference heterogeneity is important in accounting for observed dispersion in consumption and hours jel e21 e23 e31 e52

the life cycle model of consumption and saving a central implication of life cycle models is that agents smooth consumption we review the empirical evidence on smoothing at frequencies from within the year up to across a lifetime we find that life cycle models particular those which incorporate realistic features of markets and goods have more empirical successes than failures we also show that some apparent deviations from theoretical predictions imply very small welfare losses for agents finally we emphasize that the coherence of life cycle models imposes an important discipline when incorporating new features into models

schooling information and nonmarket productivity contraceptive use and its effectiveness information from two u s fertility surveys on couples knowledge about and use of specific contraceptives are used to estimate the technology of human reproduction in order to examine the association between schooling and productivity in the household sector the results indicate that more schooled couples have a wider knowledge of contraceptive methods use more efficiently those contraceptive methods for which there is little information and large scope for misuse and are better able to mitigate the effects of their biological constraints fecundity on their fertility compared to less schooled couples excerpt

a dynamic model of contraceptive choice of spanish couples in this paper we propose a simple dynamic stochastic model of sterilization and contraceptive use and we estimate its structural parameters using a sample of married couples from the 1995 spanish family and fertility survey the estimated structural model improves on previous studies in terms of its ability to rationalize observed behavior the large proportion of women contracepting at parity 0 is interpreted as evidence of precautionary contraceptive behavior allowing for simple forms of permanent unobserved heterogeneity across couples in their ability to conceive has important implications for estimates of utility and cost parameters our estimates of child valuation parameters imply that most spanish couples would have two children but significant deviations from this goal are brought about by imperfect and costly fertility control our simulations suggest that the introduction of sterilization has reduced fertility by an average of 0 2 children per couple and that the availability of more effective reversible contraceptive methods would reduce expected fertility by up to 0 4 children per couple

one warehouse multiretailer systems with centralized stock information we consider a distribution system with a central warehouse and multiple retailers the warehouse orders from an outside supplier and replenishes the retailers which in turn satisfy customer demand the retailers are nonidentical and their demand processes are independent compound poisson there are economies of scale in inventory replenishment which is controlled by an echelon stock batch transfer policy for the special case with simple poisson demand we develop an exact method for computing the long run average holding and backorder costs of the system based on this exact method we provide approximations for compound poisson demand numerical examples are used to illustrate the accuracy of the approximations we also present a numerical comparison between the average costs of a heuristic echelon stock policy and an existing lower bound on the average costs of all feasible policies

the effects of health wealth and wages on labour supply and retirement behaviour this paper estimates a life cycle model of labour supply retirement and savings behaviour in which future health status and wages are uncertain individuals face a fixed cost of work and cannot borrow against future labour pension or social security income the method of simulated moments is used to match the life cycle profiles of labour force participation hours worked and assets that are estimated from the data to those that are generated by the model the model establishes that the tax structure of the social security system and pensions are key determinants of the high observed job exit rates at ages 62 and 65 removing the tax wedge embedded in the social security earnings test for individuals aged 65 and older would delay job exit by almost one year by contrast social security benefit levels health and borrowing constraints are less important determinants of job exit at older ages for example reducing social security benefits by 20 would cause workers to delay exit from the labour force by only three months

the political economy of money evolution and impact of monetarism in the federal reserve system for almost a generation a vigorous debate has been underway over the conduct of monetary policy the central questions in this controversy are widely known what are the appropriate goals of monetary policy what are the linkages between actions to influence the cost and availability of money and credit and the behavior of real output employment and prices what are the best means in terms of targets and central bank operating techniques to accomplish the objectives of monetary policy the divergent answers which economists of different intellectual persuasion give to these questions have generated a sharp schism in the body of monetary theory on the one side are the keynesian and postkeynesian economists who have stressed the efficacy of fiscal policy for the purpose of economic stabilization on the other side are the members of the monetarist school who assign great weight to the role of monetary policy the aim of this paper is to sketch the evolution of monetarist thought inside the federal reserve system in this appraisal i have viewed the evidence from the vantage point of a member of the federal reserve board and of the federal open market committee fomc i concluded that a particularly promising approach was to observe the fomc at work in those rare instances when it set out especially to make substantive revisions in the form of the directive through which it gives instructions to the manager of the system open market account soma in the last decade there have been at least four such effortsin the years 1961 1964 65 1966 and 1970 while the focus was on the proposed changes in the directive language it is clear from the record that the debates were actually over the objectives and conduct of monetary policy thus the directive revision episodes present a unique opportunity to observe the impact on fomc members of competing ideas about monetary management i have relied primarily on the public record available in the minutes of the fomc for the years 1936 1965 and on the fomc record of policy actions through the meeting of september 21 1971 the last one in the public domain at this writ member board of governors of the federal reserve system this paper is a condensation of a more comprehensive version presented at the 84th annual meeting of the american economic association copies of the original paper may be obtained from the board washington d c 20551 i am indebted to a number of persons in the federal reserve system for assistance in the preparation of the original paper foremost among those are several of my fellow board members especially governors j dewey daane sherman j maisel george w mitchell and j l robertson who responded readily to my numerous questions and shared with me some of their recollections regarding internal debates in the federal open market committee fomc and at the board on the appropriate techniques of monetary management of course they bear no responsibility for the use or interpretation i have made of the information provided several members of the board s staff identified in the original version also helped in the preparation of the paper again i must stress that the views expressed here are my own and should not be attributed to my colleagues either on the board or among its staff

more power to the pill the impact of contraceptive freedom on women s life cycle labor supply the release of enovid in 1960 the first birth control pill afforded u s women unprecedented freedom to plan childbearing and their careers this paper uses plausibly exogenous variation in state consent laws to evaluate the causal impact of the pill on the timing of first births and extent and intensity of women s labor force participation the results suggest that legal access to the pill before age 21 significantly reduced the likelihood of a first birth before age 22 increased the number of women in the paid labor force and raised the number of annual hours worked

a two level supply chain with partial backordering and approximated poisson demand abstract we consider a two level supply chain with a number of identical independent retailers at the lower echelon and a single supplier at the upper echelon controlled by continuous review inventory policy r q each retailer experiences poisson demand with constant transportation times we assume constant lead time for replenishing supplier orders from an external warehouse to the supplier and unsatisfied retailer orders are backordered in the supplier we assume that the unsatisfied demand is partially backordered in the identical retailers the partially backordering policy is implemented in the identical retailers using an explicit control parameter b which limits the maximum number of backorders allowed to be accumulated during the lead time we develop an approximate cost function to find optimal reorder points for given batch sizes in all installations the optimal value of b in the identical retailers and the related accuracy is assessed through simulation

how prudent are consumers using data from the consumer expenditure survey this paper presents a simple test that provides an explicit estimate of the parameter in the utility function that reflects the strength of the precautionary saving motive the coefficient of relative prudence the test yields a fairly precise estimate of a small precautionary motive in fact the estimate is too small to be consistent with widely accepted beliefs about risk aversion the presence of liquidity constrained households does not appear to explain this finding and there is some evidence that self selection of households into risky environments also cannot explain the results

asset holding and consumption volatility we investigate the possibility that limited participation in asset markets and the stock market in particular might explain the lack of correspondence between the sample moments of the intertemporal marginal rate of substitution and asset returns in u k data we estimate ownership probabilities to separate likely shareholders from nonshareholders enabling us to control for changing composition effects as well as selection into the group we then construct estimates of the imrs for each of these different groups and consider their time series properties we find that the consumption growth of shareholders is more volatile than that of nonshareholders and more highly correlated with excess returns to shares in particular one cannot reject the predictions of the consumption capital asset pricing model for the group of households predicted to own both assets this is in contrast to the failure of the model when estimated on data for all households

exact and approximate evaluation of batch ordering policies for two level inventory systems we consider a two level inventory system with one warehouse and n identical retailers lead times transportation times are constant and the retailers face independent poisson demand in a previous paper we derived a recursive procedure for determining the policy costs for an average item in case of one for one replenishment policies in this paper we show how these results can be used for the exact or approximate evaluation of more general policies where both the retailers and the warehouse order in batches we compare our methods to the method recently suggested by a svoronos and p zipkin

the permanent income hypothesis and the real interest rate some evidence from panel data abstract a test of the permanent income hypothesis in panel data is formulated taking into account both the time series and cross section variation in the rate of return the over identifying restrictions of the theory rejected

evaluation of installation stock based r q policies fortwo level inventory systems with poisson demands we consider a two level inventory system with one warehouse and n retailers leadtimes transportation times are constant and the retailers face different poisson demand processes all facilities apply continuous review installation stock r q policies with different reorder points and batch quantities we show how to evaluate holding and shortage costs exactly in case of two retailers in case of more than two retailers we use the same methodology as an approximation when evaluating costs at a certain retailer the other retailers are then aggregated into a single retailer

inventory management with asset based financing most of the traditional models in production and inventory control ignore the financial states of an organization and can lead to infeasible practices in real systems this paper is the first attempt to incorporate asset based financing into production decisions instead of setting a known exogenously determined budgetary constraint as most existing models suggest we model the available cash in each period as a function of assets and liabilities that may be updated periodically according to the dynamics of the production activities furthermore our models allow different interest rates on cash balance and outstanding loans which is an enhancement over most traditional models in that inventory financed by a loan may be more expensive than that by out of pocket cash we demonstrate the importance of joint consideration of production and financing decisions in a start up setting in which the ability to grow the firm is mainly constrained by its limited capital and dependence on bank financing we then explain the motivation for asset based financing by examining the decision making at a bank and a set of retailers in a newsvendor setting

consumption over the life cycle and over the business cycle the main aim of this paper is to assess the validity of the life cycle model of consumption in particular we address an issue that has recently received much attention especially in the macroeconomic literature that of excess sensitivity of consumption growth to income growth we do this using a time series of cross sections and a novel and flexible parameterization of preferences the former allows us to address aggregation issues directly while with the latter we can allow both the discount factor and the elasticity of intertemporal substitution eis to be affected by various observable variables and lifetime wealth the main findings can be summarized as follows i the excess sensitivity of consumption growth to labor income disappears when we control for demographic variables this is true both at life cycle and business cycle frequencies ii estimation of a flexible specification of preferences indicates that the elasticity of intertemporal substitution is a function of several variables including the level of consumption the eis increases with the level of consumption as expected iii the variables that change the eis are also important in explaining why we observe excess sensitivity over the business cycle iv we are able to reconcile our results with those reported both in the macro and micro literature v in our specification the elasticity of intertemporal substitution is not very well determined this result however should be taken with care as we have not made an effort to construct a preferred specification which would probably include additional controls for labor supply behavior the evidence presented shows that the life cycle model cannot be easily dismissed indeed we believe that the model does a good job at representing consumption behavior both over the life cycle and over the business cycle