the swedish unemployment experience abstract since the 1960s sweden has sustained a remarkably low unemployment rate while the average duration of unemployment spells has been increasing over time this pattern is reproduced in an equilibrium search model incorporating progressive income taxes generous unemployment compensation and a program for preventing unemployed workers from abusing the system our analysis raises concerns about how well the swedish system is equipped to handle the current situation of high unemployment

optimal dynamic pricing for perishable assets with nonhomogeneous demand we consider a dynamic pricing model for selling a given stock of a perishable product over a finite time horizon customers whose reservation price distribution changes over time arrive according to a nonhomogeneous poisson process we show that at any given time the optimal price decreases with inventory we also identify a sufficient condition under which the optimal price decreases over time for a given inventory level this sufficient condition requires that the willingness of a customer to pay a premium for the product does not increase over time in addition to shedding managerial insight these structural properties enable efficient computation of the optimal policy numerical studies are conducted to show the revenue impact of dynamic price policies price changes are set to compensate for statistical fluctuations of demand and to respond to shifts of the reservation price for the former our examples show that using optimal dynamic optimal policies achieves 2 4 7 3 revenue improvement over the optimal single price policy for the latter the revenue increase can be as high as 100 these results explain why yield management has become so essential to fashion retailing and travel service industries

the hotel yield management with two types of room prices overbooking and cancellations abstract we consider a problem for hotel room allocations with early discount cancellations and overbooking in our model customers can book a room in discounted price if they reserve before a certain deadline the model takes overbooking into account we have expressed the expected total sale function proved it is unimodal on the number of allocated rooms for early discount and for overbooking respectively under a condition and clarified the range where the optimal solution exists we have derived an optimal allocation for early discount in a specified model without cancellations and overbooking

optimal dynamic pricing of perishable products with stochastic demand and a finite set of prices abstract consider a continuous time inventory problem in which a retailer sets the price on a fixed number of a perishable asset that must be sold prior to the time at which it perishes the retailer can dynamically adjust the price between any of a finite number of allowable prices demand for the product is poisson with an intensity that is inversely related to the price the optimal policy is piecewise constant the maximum expected revenue is nondecreasing and concave in both the remaining inventory and the time to go for a given inventory level the optimal price declines as the time at which the products perish approaches at any given time the optimal price is nonincreasing in the number of items remaining unsold these results are extended to i the case in which the prices and corresponding demand intensities depend on the time to go and ii the case in which the retailer can restock to meet demand at a unit cost after the initial inventory has been sold

pricing and capacity rationing for rentals with uncertain durations we consider a rental firm with two types of customers contract customers pay fixed prenegotiated rental fees and expect a high quality of service walk in customers have no contractual relations with the firm and are shopping for price given multiple contract and walk in classes the rental firm has to decide when to offer service to contract customers and what fees to charge walk in customers for service we formulate this rental management problem as a problem in stochastic control and characterize optimal policies for managing contract and walk in customers we also consider static myopic controls that are simpler to implement and we analytically establish conditions under which these policies perform optimally complementary numerical tests provide a sense of the range of systems for which myopic policies are effective

options for economic and political reform in sweden sweden assar lindbeck per molander torsten persson olof peterson agnar sandmo birgitta swedenborg and niels thygesen this paper summarizes an official report to the swedish government and general public the economic crisis in sweden is explained by both system failures and specific policy mistakes the system failures include distorted incentives and markets and inappropriate and outdated institutions the deep recession and extraordinary rise in unemployment started as a collision between inflationary wage development and attempts to pursue a hard currency policy the resulting loss of international competitiveness in the tradable sector was accompanied by increased real interest rates collapsing real estate prices and a related financial crisis following the floating of the swedish krona in november 1992 the main problem became a domestic demand collapse which has been accentuated by a spectacular rise in the household saving rate the report emphasizes that good policy advice is not enough it is also necessary to analyse and reform the institutions which continually produce undesired outcomes with respect not only to macroeconomic stability but also economic efficiency and growth the proposed institutional reforms are designed to restore a highly competitive market system and to facilitate a responsible fiscal stabilization programme this would also enhance the medium run credibility of government policies and provide scope for a more expansionary policy in the short run

analysis of deterministic lp based booking limit and bid price controls for revenue management we study the performance of two popular and widely used heuristics for revenue management known as the booking limit and bid price controls in contrast to a recent result in the literature where frequent re solvings of a certain heuristic are shown to significantly reduce revenue loss we show that the asymptotic revenue loss of either booking limit or bid price control cannot be reduced regardless of the choice of re solving times and the frequency of re solving moreover we also show that further variations within the policy classes such as nested instead of partition booking limit or certainty equivalent instead of additive bid price are simply indistinguishable in terms of their order of revenue loss under frequent re solvings this negative result highlights the limitation of re solving deterministic linear programs when the solution is interpreted as either a booking limit or a bid price finally we briefly discuss how to modify the traditional booking limit control to make it more responsive

dynamic capacity management with substitution we examine a multiperiod capacity allocation model with upgrading there are multiple product types corresponding to multiple classes of demand and the firm purchases capacity of each product before the first period within each period after demand arrives products are allocated to customers customers who arrive to find that their product has been depleted can be upgraded by at most one level we show that the optimal allocation policy is a simple two step algorithm first use any available capacity to satisfy same class demand and then upgrade customers until capacity reaches a protection limit so that in the second step the higher level capacity is rationed we show that these results hold both when all capacity is salvaged at the end of the last demand period as well as when capacity can be replenished in the latter case an order up to policy is optimal for replenishment although finding the optimal protection limits is computationally intensive we describe bounds for the optimal protection limits that take little effort to compute and can be used to effectively solve large problems using these heuristics we examine numerically the relative value of strictly optimal capacity and dynamic rationing the value of perfect demand information and the impact of demand and economic parameters on the value of optimal substitution

credibility debt and unemployment ireland s failed stabilization ireland s disinflation rudiger dornbusch disinflation requires a switch to tough policies if these are fully and immediately reflected in expectations and actual prices there need be little output cost of disinflation this paper analyses the stabilization programme in ireland in the 1980s it may be that ems membership offers a credibility bonus by joining the ems playing by the rules of fixed exchange rates and tying the currency to german price stability a country can achieve a dramatic turnaround in expectations inflation and long interest rates but the evidence shows international disinflation in the 1980s was not limited to ems members the irish example demonstrates a second lesson disinflation and tight money have been accompanied by a serious public debt problem and soaring unemployment unless these problems can be tackled it may become necessary in future to resort once more to inflation and the printing press long interest rates suggest that the bond market does not yet take such fear seriously

optimal dynamic auctions for revenue management we analyze a dynamic auction in which a seller withc units to sell faces a sequence of buyers separated intot time periods each group of buyers has independent private values for a single unit buyers compete directly against each other within a period as in a traditional auction and indirectly with buyers in other periods through the opportunity cost of capacity assessed by the seller the number of buyers in each period as well as the individual buyers valuations are random the model is a variation of the traditional single leg multiperiod revenue management problem in which consumers act strategically and bid for units of a fixed capacity over time for this setting we prove that dynamic variants of the first price and second price auction mechanisms maximize the seller s expected revenue we also show explicitly how to compute and implement these optimal auctions the optimal auctions are then compared to a traditional revenue management mechanism in which list prices are used in each period together with capacity controls and to a simple auction heuristic that consists of allocating units to each period and running a sequence of standard multiunit auctions with fixed reserve prices in each period the traditional revenue management mechanism is proven to be optimal in the limiting cases when there is at most one buyer per period when capacity is not constraining and asymptotically when the number of buyers and the capacity increases the optimal auction significantly outperforms both suboptimal mechanisms when there are a moderate number of periods capacity is constrained and the total volume of sales is not too large the benefit also increases when variability in the dispersion in buyers valuations or in the number of buyers per period increases

revenue management for operations with urgent orders this article is motivated by the case of a company manufacturing industrial equipment that faces two types of demand on the one hand there are the so called regular orders for installations or refurbishing of existing facilities these orders have a relatively long lead time on the other hand there are urgent orders mostly related to spare parts when a facility has a breakdown the delay in such case is much shorter but higher margins can be obtained we study the order acceptance problem for a firm that serves two classes of demand over an infinite horizon the firm has to decide whether to accept a regular order or equivalently how much capacity to set aside for urgent orders in order to maximize its profit we formulate this problem as a multi dimensional markovian decision process mdp we propose a family of approximate formulations to reduce the dimension of the state space via aggregation we show how our approach can be used to compute bounds on the profit associated with the optimal order acceptance policy finally we show that the value of revenue management is commensurate with the operational flexibility of the firm

multiperiod airline overbooking with a single fare class consider a multiperiod airline overbooking problem that relates to a single leg flight and a single service class passengers may cancel their reservations at any time including being no shows at flight time at that time the airline bumps passengers in excess of flight capacity and pays a penalty for so doing we give conditions on the fares refunds and distributions of passenger demand for reservations and cancellations in each period and on the bumping penalty function that ensure that a booking limit policy is optimal i e in each period the airline accepts reservation requests up to a booking limit if the number of initial reservations is less than that booking limit and declines reservation requests otherwise the optimal booking limits are easily computed we give conditions under which the optimal booking limits are monotone in the time to flight departure the model is applied to the discount allocation problem in which lower fare classes book prior to higher fare classes

the welfare costs of union wage compression abstract this paper calculates the quantitative significance of the welfare costs of union wage compression this is done in a dynamic general equilibrium model with overlapping generations where agents choose both schooling human capital and assets physical capital the labor market in this model is characterized as a right to manage contract which allows unions to compress wage differentials between high and low skilled workers by implementing a binding minimum wage this paper shows that when labor markets are competitive even low levels of wage compression lead to large welfare losses since wage compression creates costly unemployment among low skilled workers the effect of wage compression on the supply of skilled labor however is rather small since the disincentive effect of a lower high skilled wage is to a large extent offset by a lower opportunity cost of schooling due to higher unemployment

estimates of gender differences in firm s access to credit in sub saharan africa based on firm level data from 16 sub saharan african countries we show how three different measures of credit constraints lead to three different estimates of gender differences in manufacturing firms credit situation using a perception based credit constraint measure female owned firms appear relatively more constrained than male owned firms using formal financial access data we find no gender effect finally using direct information on credit constraints male owned small firms appear disadvantaged furthermore we show a strong size gradient in the gender gap for the two measures for which we find significant gender differences

revenue management by sequential screening abstract using a mechanism design approach we consider a firm s optimal pricing policy when consumers are heterogeneous and learn their valuations at different times we show that by offering a menu of advance purchase contracts that differ in when and for how much the product can be returned a firm can more easily price discriminate between privately informed consumers in particular we show that screening on when the return option can be exercised increases firm profits relative to screening on the size of the refund alone only if the expected gains from trade are higher for consumers who learn later we show that in some settings mean preserving spread the firm can achieve the complete information profits and analyze the optimal contract in other settings first order stochastic dominance in which the first best allocation is not always feasible

dynamic pricing through discounts for optimizing multiple class demand fulfillment in a multiple customer class model of demand fulfillment for a single item we consider the use of dynamic price discounts to encourage backlogging of demand for customer classes denied immediate service customers are assumed to arrive over several stages in a period and customer classes are distinguished by their contractual price and sensitivity to discounts through dynamic programming we determine the optimal discounts to offer assuming a linear model for the sensitivity of customers to such inducements we show that customers are served in class order and allocation of inventory to demand is determined by considering the current number of customers backlogged as well as the current inventory position through comparison to a naive supplier allocating inventory first come first served with no discounting we show that profits are primarily influenced by the allocation of capacity and the use of price discounts primarily benefits the second class customers overall fill rate heuristics for implementation of the solution in real time settings are given

robustness of capacity rationing policies a recent paper discusses a capacity rationing policy that allows make to order manufacturing firms encountering expected total demand in excess of available capacity to discriminate between two classes of products one yielding a higher profit contribution per unit of capacity allocated to it than the other the result is a selective rejection of orders for the class with lower unit contribution yielding an increase in total profit when compared to a base case that implements no capacity rationing implementation of the policy requires forecasts of demand parameters for both product classes in this paper we test the sensitivity of the capacity rationing policy to forecast errors in these parameters the results indicate that on average the rationing policy is quite robust in improving profit even when actual demands are approximately twenty percent different from forecast values

revenue management with limited demand information in this paper we consider the classical multifare single resource leg problem in revenue management for the case where demand information is limited our approach employs a competitive analysis which guarantees a certain performance level under all possible demand scenarios the only information required about the demand for each fare class is lower and upper bounds we consider both competitive ratio and absolute regret performance criteria for both performance criteria we derive the best possible static policies which employ booking limits that remain constant throughout the booking horizon the optimal policies have the form of nested booking limits dynamic policies which employ booking limits that may be adjusted at any time based on the history of bookings are also obtained we provide extensive computational experiments and compare our methods to existing ones the results of the experiments demonstrate the effectiveness of these new robust methods

perishable asset revenue management with markovian time dependent demand intensities many industries face the problem of selling a fixed stock of items over a finite horizon these industries include airlines selling seats before planes depart hotels renting rooms before midnight theaters selling seats before curtain time and retailers selling seasonal items with long procurement lead times given a sunk investment in seats rooms or winter coats the objective for these industries is to maximize revenues in excess of salvage value when demand is price sensitive and stochastic pricing is an effective tool to maximize expected revenues in this paper we address the problem of deciding the optimal timing of price changes within a given menu of allowable possibly time dependent price paths each of which is associated with a general poisson process with markovian time dependent predictable intensities we show that a set of variational inequalities characterize the value functions and the optimal possibly random time changes in addition we develop an efficient algorithm to compute the optimal value functions and the optimal pricing policy

pricing and revenue management the value of coordination the integration of systems for pricing and revenue management must trade off potential revenue gains against significant practical and technical challenges this dilemma motivates us to investigate the value of coordinating decisions on prices and capacity allocation in a stylized setting we propose two pairs of sequential policies for making static decisions on pricing and revenue management that differ in their degree of integration hierarchical versus coordinated and their pricing inputs deterministic versus stochastic for a large class of stochastic price dependent demand models we prove that these four heuristics admit tractable solutions satisfying intuitive sensitivity properties we further evaluate numerically the performance of these policies relative to a fully coordinated model which is generally intractable we find it interesting that near optimal performance is usually achieved by a simple hierarchical policy that sets prices first based on a nonnested stochastic model and then uses these prices to optimize nested capacity allocation this tractable policy largely outperforms its counterpart based on a deterministic pricing model jointly optimizing price and allocation decisions for the high end segment improves performance but the largest revenue benefits stem from adjusting prices to account for demand risk this paper was accepted by yossi aviv operations management

capacity rationing decision procedures with order profit as a continuous random variable abstract when expected demand is more than available capacity a make to order manufacturer should take the more profitable orders and reject the less profitable orders in order to better allocate its limited capacity and maximize its profit however various orders will arrive at different times in the future so the manufacturer cannot look at all the order inquiries at the same time and choose the most profitable ones when an order inquiry arrives the manufacturer must promptly determine without knowing exactly what the future orders might be whether to accept the order or to reject the order thus reserving the capacity for future more profitable orders this study focuses on such an order selection decision problem under the following assumptions 1 the arrival of future customer orders is a poisson process 2 the capacity requirement of a future customer order is a continuous random variable and 3 the profit per unit capacity used by an order is also a continuous random variable under the stochastic problem assumptions this study investigates two decision procedures that determine whether to accept or to reject an order inquiry based on the available information including 1 current available manufacturing capacity 2 capacity requirement by the order and 3 the profit per unit capacity of the order one procedure is called static probability capacity rationing decision procedure spcr the other one is called dynamic stochastic capacity rationing decision procedure dscr simulation experiments are conducted to validate the proposed procedures an optimal solution method that uses 0 1 knapsack problem formulation to obtain the decisions with perfect information is used to measure the effectiveness of the proposed procedures the results show that the approach utilizing dscr outperforms other approaches by providing the highest profit and is also very robust under various problem conditions

sex differences in access to a small enterprise development fund in peru abstract in an attempt to ensure that the direct benefits of an urban small enterprise project were reaching women the industrial bank of peru undertook a study of the constraints to women s access to a major credit program it had initiated in the squatter settlements pueblos jo venes of lima the study found that the low proportion of women among the program s borrowers was not due to more women being rejected when they applied for loans but to the fact that few women applied high collateral requirements and complicated application procedures deterred women from applying those women who did apply received smaller loans than men and were concentrated in garment manufacture services and commerce taking these factors into account the authors make recommendations for ways to enhance women s participation in the credit scheme and similar small enterprise programs in the developing countries

design and evaluation of a dynamic capacity apportionment procedure abstract deploying a decision theory based approach we develop a heuristic for short term constrained capacity allocation to multiple product classes in make to order manufacturing attempting to maximize profit by discriminating between product classes efficacy of the heuristic is evaluated by comparing its performance to a base case and an upper bound under a wide variety of operational conditions such as variations in profit attractiveness capacity tightness customer order size structure customer order rate structure and demand coefficient of variation considering three different scenarios of time variant order rate of products the results indicate that the heuristic is effective in obtaining increased profit when capacity is very tight and products are well differentiated on average it yields an increase of 9 38 in total profit with a concomitant decrease of 0 85 in capacity utilization the results of this study serve to highlight the value of proactively seeking to differentiate products particularly when demand exceeds capacity

ethnicity and credit in african manufacturing abstract this paper investigates whether market interaction can by itself perpetuate the lack of ethnic diversity that is observed in the business communities of many developing countries using case study data on manufacturing firms in kenya and zimbabwe we find no evidence that blacks or women are disadvantaged in the attribution of bank credit once we control for firm size and other observable characteristics in contrast an ethnic and gender bias is noticeable in the attribution of supplier credit although we cannot rule out the presence of discrimination the bulk of the evidence indicates that network effects play an important role in explaining this bias

revenue management under a general discrete choice model of consumer behavior customer choice behavior such as buy up and buy down is an important phenomenon in a wide range of revenue management contexts yet most revenue management methodologies ignore this phenomenon or at best approximate it in a heuristic way in this paper we provide an exact and quite general analysis of this problem specifically we analyze a single leg reserve management problem in which the buyers choice behavior is modeled explicitly the choice model is very general simply specifying the probability of purchase for each fare product as a function of the set of fare products offered the control problem is to decide which subset of fare products to offer at each point in time we show that the optimal policy for this problem has a quite simple form namely it consists of identifying an ordered family of efficient subsets s 1 s m and at each point in time opening one of these sets s k where the optimal index k is increasing in the remaining capacity x and decreasing in the remaining time that is the more capacity or less time available the further the optimal set is along this sequence we also show that the optimal policy is a nested allocation policy if and only if the sequence of efficient sets is nested that is s 1 s 2 s m moreover we give a characterization of when nesting by fare order is optimal we also develop an estimation procedure for this setting based on the expectation maximization em method that jointly estimates arrival rates and choice model parameters when no purchase outcomes are unobservable numerical results are given to illustrate both the model and estimation procedure

access to credit by firms in sub saharan africa how relevant is gender the literature on the determinants of firms financing constraints has paid little attention to gender as a determinant of access to finance using data for 34 342 firms from 90 developing countries the paper analyzes the determinants of firms financing constraints and assesses whether female owned firms are more financially constrained than male owned businesses the results show that female owned firms in sub saharan africa are more likely to be financially constrained than male owned firms but there is no gender gap in other developing regions the gender gap in sub saharan africa is robust to variations in specifications and econometric estimation procedures

an analysis of bid price controls for network revenue management bid prices are becoming an increasingly popular method for controlling the sale of inventoryin revenue management applications in this form of control threshold or bid prices are set for the resources or units of inventory seats on flight legs hotel rooms on specific dates etc and a product a seat in a fare class on an itinerary or room for a sequence of dates is sold only if the offered fare exceeds the sum of the threshold prices of all the resources needed to supply the product this approach is appealing on intuitive and practical grounds but the theory underlying it is not well developed moreover the extent to which bid price controls represent optimal or near optimal policies is not well understood using a general model of the demand process we show that bid price control is not optimal in general and analyze why bid price schemes can fail to produce correct accept deny decisions however we prove that when leg capacities and sales volumes are large bid price controls are asymptotically optimal provided the right bid prices are used we also provide analytical upper bounds on the optimal revenue in addition we analyze properties of the asymptotically optimal bid prices for example we show they are constant over time even when demand is nonstationary and that they may not be unique

mathematical programming for network revenue management revisited mathematical programming models for airline seat inventory control provide booking limits and bid prices for all itineraries and fare classes e l williamson airline network seat inventory control methodologies and revenue impacts ph d thesis massachusetts institute of technology cambridge ma 1992 finds that simple deterministic approximation methods based on average demand often outperform more advanced probabilistic heuristics we argue that this phenomenon is due to a booking process that includes nesting of the fare classes which is ignored in the modeling phase the differences in the performance between these approximations are studied using a stochastic programming model that includes the deterministic model as a special case our study carefully examines the trade off between computation time and the aggregation level of demand uncertainty with examples of a multi leg flight and a single hub network

oaxaca blinder as a reweighting estimator the classic regression based estimator of counterfactual means studied by ronald oaxaca 1973 and alan blinder 1973 is shown to constitute a propensity score reweighting estimator based upon a linear model for the conditional odds of being treated

unemployment persistence does the size of the shock matter one of the stylized facts of unemployment is that shifts in its mean rate between decades and half decades account for most of its variance in this paper we use a statistical analysis based on markov switching regression models to identify the dates of infrequent changes in the mean of the unemployment rate series of fifteen countries we find that in most countries unemployment persistence is much reduced once the infrequently changing mean rate induced by large shocks to unemployment has been removed we conclude that the observed persistence in unemployment appears to be consistent with multiple equilibria models and models with an endogeneous natural rate 1998 john wiley sons ltd

eurosclerosis and the sclerosis of objectivity on the role of values among economic policy experts schumpeter once observed that frequently economists not content with their scientific task yield to the call of public duty and to their desire to serve their country and their age by acting as policy experts and policy advocates schumpeter i949 p 346 this raises the issue discussed by gunnar myrdal i958 p 4 of whether social scientists can be practical and at the same time objective what is the relation between wanting to understand and wanting to change society how can the search for true knowledge be combined with moral and political valuations myrdal s questions point to serious but rarely discussed issues of objectivity and values when economists and other social scientists become involved in the making of public policy often in areas of conflict between major interest groups in western societies see also myrdal i 929 i 958 blaug i 992 ch 5 1 in everyday life the roles of the policy expert and the policy advocate tend to merge this mixing can be understood in terms of sen s distinction between b sic values supposed to apply under all conceivable circumstances and nonbasic values expected to hold only under specified factual circumstances sen i970 p 59 policymaking is typically concerned with non basic values economists can change the goals and choices of policymakers by changing their views of what the facts are by acting as policy advisors many brilliant economists have undoubtedly done excellent service to their countries and their times in this context names such as that of john maynard keynes come to many people s mind however it has also been noted that economic policy advisers frequently rely on anecdotal evidence and misleading statistics stigler i965 rivlin i986 krugman i994 like bad weather this situation has typically been accepted as a necessary evil from the point of view of scientific progress as well as the democratic process however the intellectual responsibility of academic policy experts must be increased with only the threat of losing intellectual credibility as a potential sanction from time to time they should therefore be required to

african smes networks and manufacturing performance abstract this paper examines the role of private support institutions in determining small and medium enterprise smes growth and performance in sub saharan africa ssa it finds that smes in ssa get around market failures and lack of formal institutions by creating private governance systems in the form of long term business relationships and tight ethnically based business networks there are important links between these informal governance institutions and sme performance networks raise the performance of insiders and in the sparse business environments of the ssa region have attendant negative consequences for market participation of outsiders such as indigenous african smes this is indicated through the determinants of access to supplier credit policy interventions will be needed to improve the platform for relation based governance mechanisms and to address the exclusionary effects of tight networks

price discrimination on booking time abstract even if consumers are forward looking and free to choose when to purchase a firm can price discriminate on booking time if consumers learn their valuations at different times and consumers who learn later have higher valuations the model is related to our work on optimal screening with returns contracts akan ata and dana 1 but here we consider a simpler binary valuation distribution and consider more realistic consumer learning assumptions the main contribution is to show that the profitability of screening on time is robust to relaxing the assumption that consumers learn instantaneously in addition to analyzing a bad news model in which information arrives gradually we characterize a general bound on consumer optimism that guarantees that the instantaneous learning results are robust

post keynesianism socialisation of investment and swedish wage earner funds this paper analyses the performance of one of the most controversial of recent economic policy experiments namely swedish wage earner funds wefs it examines the ability of the wefs to meet macroeconomic financial and democratic objectives the analysis indicates a favourable financial performance but little significant democratisation macroeconomic influence was constrained by the limited size of the scheme and though associated with positive changes in economic variables the experiment was ultimately overwhelmed by the collapse of an asset price bubble nevertheless the performance of the wefs has legitimised the concept of collective investment funds as an economic policy instrument copyright 2006 oxford university press

access to finance in sub saharan africa is there a gender gap we show the existence of an unconditional gender gap in sub saharan africa however when key observable characteristics of the enterprises or individuals are taken into account the gender gap disappears in the case of enterprises we explain our finding with differences in key characteristics and a potential selection bias in the case of individuals the lower use of formal financial services by women can be explained by gender gaps in other dimensions related to the use of financial services such as their lower level of income and education and by their household and employment status

managing capacity in tightly constrained systems abstract many make to order firms face total expected demand in excess of available capacity this is particularly true in the short range for capital intensive firms such as those in the flow process industry firms making short life cycle products such as those in high fashion apparel industry and printing shops in such situations the manager is left with the difficult task of allocating the available capacity between competing classes of products and or customers at the same time the manager is faced with the challenge of achieving delivery dependability and speed in order to stay competitive in this paper i describe the problem contrast it with a class of problems known as perishable asset revenue management problems review recent literature that presents alternative approaches for managing capacity such as capacity rationing improved coordination mechanisms and subcontracting and discuss fruitful avenues for future research

is the welfare state necessarily an obstacle to economic growth abstract the welfare state is widely held to be one of the elements responsible for slower economic growth in europe this paper seeks to clarify the nature of this indictment and to suggest that there is a plausible case for defence of the welfare state

revenue management without forecasting or optimization an adaptive algorithm for determining airline seat protection levels we investigate a simple adaptive approach to optimizing seat protection levels in airline revenue management systems the approach uses only historical observations of the relative frequencies of certain seat filling events to guide direct adjustments of the seat protection levels in accordance with the optimality conditions of brumelle and mcgill 1993 stochastic approximation theory is used to prove the convergence of this adaptive algorithm to the optimal protection levels in a simulation study we compare the revenue performance of this adaptive approach to a more traditional method that combines a censored forecasting method with a common seat allocation heuristic emsr b

a taxonomy and research overview of perishable asset revenue management yield management overbooking and pricing this paper proposes the term perishable asset revenue management to denote the field that combines the areas of yield management overbooking and pricing for perishable assets after summarizing the characteristics common to problems in this field the paper discusses the objectives and constraints faced by decision makers then it offers a comprehensive taxonomy with 14 different elements and reviews the research that has been done related to each element finally it suggests some important areas of future research that can help bridge the gap between theory and application

airline seat allocation with multiple nested fare classes this paper addresses the problem of determining optimal booking policies for multiple fare classes that share the same seating pool on one leg of an airline flight when seats are booked in a nested fashion and when lower fare classes book before higher ones we show that a fixed limit booking policy that maximizes expected revenue can be characterized by a simple set of conditions on the subdifferential of the expected revenue function these conditions are appropriate for either the discrete or continuous demand cases these conditions are further simplified to a set of conditions that relate the probability distributions of demand for the various fare classes to their respective fares the latter conditions are guaranteed to have a solution when the joint probability distribution of demand is continuous characterization of the problem as a series of monotone optimal stopping problems proves optimality of the fixed limit policy over all admissible policies a comparison is made of the optimal solutions

a multiproduct dynamic pricing problem and its applications to network yield management a firm has inventories of a set of components that are used to produce a set of products there is a finite horizon over which the firm can sell its products demand for each product is a stochastic point process with an intensity that is a function of the vector of prices for the products and the time at which these prices are offered the problem is to price the finished products so as to maximize total expected revenue over the finite sales horizon an upper bound on the optimal expected revenue is established by analyzing a deterministic version of the problem the solution to the deterministic problem suggests two heuristics for the stochastic problem that are shown to be asymptotically optimal as the expected sales volume tends to infinity several applications of the model to network yield management are given numerical examples illustrate both the range of problems that can be modeled under this framework and the effectiveness of the proposed heuristics the results provide several fundamental insights into the performance of yield management systems

the politics of market socialism the debate over market socialism has ignored the importance of the assumptions about the objectives of politicians in determining resource allocation theory and evidence suggest that totalitarian socialism does not lead to efficient resource allocation because dictators do not maximize social welfare but democratic governments have political objectives different from social welfare as well the authors argue that because these governments command greater resources have more control rights under socialism democratic socialism even if it could exist is a less efficient system than democratic capitalism thus the political case against market socialism is even stronger than the economic case

the myth of female credit discrimination in african manufacturing abstractwe examine credit constraint differentials between male and female manufacturing entrepreneurs using firm data from 16 sub saharan africa countries small enterprises owned by female entrepreneurs are less likely to be credit constrained compared to their male counterparts while this is reversed for medium sized enterprises a generalised oaxaca blinder decomposition shows that the gap is predominantly a pure gender effect we argue that this finding is mainly due to female favouritism in loans to micro and small firms because the gap is reversed for medium sized enterprises and because we find no sign of superior female entrepreneurial performance in observable indicators

barking up the wrong tree measuring gender gaps in firm s access to finance abstractthe literature on gender based discrimination in credit markets is recently expanding but the results are not yet definitive and have not been generally agreed upon this paper exploits a new dataset on barbados jamaica and trinidad and tobago which provides detailed information about female ownership and management in firms for investigating the existence of a gender gap in access to finance the evidence presented herein suggests that more precise measures of the gender composition of the firm show that women led businesses are more likely to be financially constrained than other comparable firms

discrete order admission atp model with joint effect of margin and order size in a mto environment abstract swarming demands and seasonality periodically induce a stringent capacity problem in the made to order mto b2b environment desirable order admission is a tactic with minimal application cost for handling this problem a real time order admission problem with limited major customer population and batch size demand with heterogeneous distributions is modeled as a dynamic and stochastic knapsack problem the optimality of the markovian deterministic reward threshold policy is verified optimal policy basic policy and the capacity rationing method are compared in the designed experiment the numerical results suggest great potential for increasing profit using the optimal order admission policy for mto businesses

structural properties of markov modulated revenue management problems abstract the admission decision is one of the fundamental categories of demand management decisions in the dynamic model of the single resource capacity control problem the distribution of demand does not explicitly depend on external conditions however in reality demand may depend on the current external environment which represents the prevailing economic financial social or other factors that affect customer behavior we formulate a markov decision process mdp to maximize expected revenues over a finite horizon that explicitly models the current environment we derive some structural results of the optimal admission policy including the existence of an environment dependent thresholds and a comparison of threshold levels in different environments we also present some computational results which illustrate these structural properties finally we extend some of the results to a related dynamic pricing formulation

pricing non storable perishable goods by using a purchase restriction with an application to airline fare pricing abstract the aim of this paper is to address the pricing problem of non storable perishable goods or services such as airline seats and hotel rooms by incorporating the use of purchase restrictions such as the advance booking requirement that is commonly used by airlines and hotels we will show that there exists an optimal pricing policy of at most three prices which can be obtained by solving a series of linear programming problems we will demonstrate that when applied to airline fare pricing the monotonicity condition of the model is equivalent to the requirement that business travelers are less price elastic than leisure travelers we will further illustrate the applicability of the model through a numerical example in the context of airline fare pricing by incorporating the impact of various fences