union wage policy the importance of labour mobility and the degree of centralization with endogenous product prices nationwide wage setting gives lower unemployment than decentralized wage setting however intermediate level wage setting may give more unemployment than both completely decentralized and completely centralized wage setting the main part of the paper considers a dynamic model which includes flows of workers between firms and in and out of unemployment with less than full centralization the wages chosen by unions are lower the higher is the degree of labor mobility wages are also lower the higher is the degree of centralization unless labor mobility is very high copyright 1991 by the london school of economics and political science

note periodic review s s policies for joint replenishment inventory systems this note deals with the joint replenishment problem with stochastic demands a new class of policies called ps s policy is proposed for this problem the proposed policy uses independent periodic review s s policies for each item results on test problems show that the proposed policy is superior to other classes of policies for the problem

bargaining and the timing of investment the joint determination of the timing of investment and wage bargaining is modelled two cases are considered a there is an alternating offer bargaining game over binding wage contracts and production is possible only when agreement is reached b there are no binding contracts so revenue is divided in period by period bargaining post investment investment can occur earlier in case b than in case a and the equilibrium in case b can pareto dominate the equilibrium with binding contracts these conclusions depend on players discount factors

efficiency wages and local wage bargaining in the literature on wage drift it is often argued that strikes or work to rule practices are used to force employers to pay a wage rate that exceeds the contract wage here we introduce the efficiency wage argument as a foundation for bargaining about wage drift contrary to the view in most bargaining models where firms and unions struggle to divide a fixed pie given employment we take the relation between wages and revenues explicitly into account the implications for wages and employment appear to differ not only with respect to the order of magnitude but also in a qualitative sense

corporate governance and innovation a survey abstract the traditional economics of innovation inspired by schumpeter and more recent advances on his work seem unable to explain why firms with similar external conditions may show greatly different performance in innovation contrastingly the literature on corporate governance provides some useful insights for understanding corporate innovation activity to the extent that such literature examines the economic effects of different modes of coordination between firm members the process through which individuals integrate their human and physical resources within the firm is central to the dynamics of corporate innovation this paper provides the first survey of the literature on this issue we start by discussing how various theoretical approaches to the analysis of the firm deal with technological innovation we then describe three main channels corporate ownership corporate finance and labour through which a system of corporate governance shapes a firm s innovation activity finally we examine the relationship between country level institutional settings national patterns of corporate governance and the aggregate innovation activity of corporations we conclude by suggesting that future research should focus more deeply on the interrelation between the various dimensions of corporate governance and on their joint effect on firm innovation

coordinated replenishments in inventory systems with correlated demands abstract demand correlation among different inventory items is common in real life multi item inventory systems however this phenomenon has not received sufficient attention in the existing inventory literature in this paper we construct a markovian model for a two item inventory system with correlated demands and coordinated replenishments we obtain an expression for the long run total cost per unit of time under the can order replenishment policy for the scenario with independent replenishments the explicit formula for the long run total cost per time unit can be derived which leads to analytical solutions for the optimal policies we then present numerical examples of the optimal can order policies and discuss some managerial insights regarding demand correlation and replenishment coordination our numerical results also suggest a possible heuristic method for obtaining can order replenishment policies for multi item systems

collective bargaining and the interindustry wage structure international evidence this paper studies collective bargaining and industry wage levels using microdata and quantile regression techniques for the united states britain west germany austria sweden and norway for the 1980s the united states has higher industry wage differentials and union wage effects than other countries with particularly large impacts at the bottom of the distribution european wage structures are more compressed at the bottom for both nonunion and union workers relative to the united states with larger differences for nonunion workers these findings suggest more coordination contract extension and spillover to nonunion workers and more binding industry wage floors outside the united states

deterministic eoq with partial backordering and correlated demand caused by cross selling abstract there has been much work regarding the deterministic eoq with partial backordering the majority of these studies assume no correlation in sales so independent demands across items is applied in the models however it is generally recognized that cross selling effects between items often appear in real contexts thus incorporating such effects in the inventory model in the form of correlated demands makes it of more practical relevance in this paper the authors address a two item inventory system where the demand of a minor item is correlated to that of a major item because of cross selling we firstly present a two item eoq model with identical order cycles where the unmet demand of the major item can be partially backordered with lost sales whereas the demand of the minor item must be met without stockouts this model is further extended to fit a more practical case where the order cycle of the major item is an integer multiple of that of the minor item the optimal solutions of the two models as well as the inventory decision procedures are also developed comparative analysis on these two eoq models has been drawn in the computational study which presents some insights into the parameter effect on the optimal inventory policy

real wage adjustment and employment policies in the nordic countries nordic employment lars calmfors and ragnar nymoen sweden and norway but also finland have managed to avoid the general western european rise in unemployment the article discusses to what extent this can be explained by a smoothly functioning wage setting system and by active labour market policies the analysis confirms earlier findings of an unusually large responsiveness of wages to unemployment in sweden and norway it is however questionable whether this can be explained by centralized bargaining nor do the authors find any evidence that corporatist tax wage bargains should have contributed to wage restraint the absence of hysteresis effects may be one explanation of why unemployment rises were easily reversed the most controversial finding is that active labour market policies may have strong wage raising effects if so labour market programmes may actually reduce regular employment and even increase open unemployment the authors argue that a reduced rather than an increased emphasis on labour market policies may have been an important factor for real wage restraint especially in sweden this may be an important lesson for those who regard extensive labour market programmes of the swedish type as a blueprint to follow

a multi item periodic replenishment policy with full truckloads abstract in this paper we consider a stochastic multi item inventory problem a retailer sells multiple products with stochastic demand and is replenished periodically from a supplier with ample stock at each order instant it is decided which product to order and how much to order for the delivery of the products trucks with a finite capacity are available the dispatched trucks arrive at the retailer after a constant leadtime and with each truck fixed shipping costs are charged independent on the number of units shipped additionally linear holding and backorder costs at the end of a review period are considered since fixed transportation costs are high coordination of orders and full truckload shipments can benefit from economies of scale we propose a dynamic order up to policy where initial ordersizes can be reduced as well as enlarged to create full truckloads we show how to compute the policy parameters and in a detailed numerical study we compare our policy with a lower bound and an uncoordinated periodic replenishment policy an excellent cost performance of the proposed policy can be observed when average time between two shipments is not too large and fixed shipping costs are high

a heuristic joint replinishment policy for the case of heterogeneity among items abstract the q s s policy is considered among the best for solving the well known stochastic joint replenishment problem however it has some shortcomings if much heterogeneity exists among the items consequently a new heuristic control policy is constructed the cornerstone is a policy iteration improvement step assuming a single possibility for making a joint order and thus to deviate from the rule that the items are governed by independent re order and order up to s s policies but this policy iteration improvement step is done repeatedly at each demand epoch it is only required the development of one dimensional value functions of state variables in order to accomplish the policy iteration improvement step knowledge about good order up to values is important furthermore a relaxation parameter is introduced such that one can make it easier or more difficult to issue a joint order when following the policy iteration improvement step finally in case a joint order is made a vector of can order points is used to include additional items the policy is denoted a c s policy numerical results shows that the new policy performs significantly better than the q s s policy for cases with heterogeneity among items furthermore from a given optimal can order policy one can construct a better c s policy

bargaining structures and delay in innovation it is sometimes argued that fears about the employment consequences of introducing new technology may lead unions to wish to delay innovations and this may reduce incentives for firm to carry out r d we explore these issues in a model of two countries that compete over both market share and r d and we restrict attention to cases where unions would wish to delay innovation we show that allowing unions to bargain over the timing of innovation need not reduce the possibility of a firm successfully competing for r d however simulations suggest that for a particular model allowing unions to delay innovation does not help a firm compete over r d

long term relationships governed by short term contracts this paper studies the effects of contract duration on the incentive to invest in a relationship when its parties are rational and have perfect information and contracts are complete ex cept that short term contracts specify only current period actions t hen short term contracting distorts investment decisions only when t he efficient plan involves mainly sunk cost investment and the relati onship plays a consumption smoothing role there is a general but no t universal tendency to underinvest copyright 1988 by american economic association

estimation of price cost margins and union bargaining power for belgian manufacturing abstract this paper extends hall s 1988 hall r e 1988 the relationship between price and marginal cost in us industry journal of political economy 96 921 947 methodology to analyze imperfections in both the product and the labor market for firms in the belgian manufacturing industry over the period 1988 1995 we investigate the heterogeneity in price cost mark up and workers bargaining power parameters among 18 sectors within the manufacturing industry as well as the relationship between both parameters using a sample of more than 7000 firms our gmm results indicate that ignoring imperfection in the labor market leads to an underestimation of the price cost margin evaluated at perfect competition in the labor market these findings are confirmed in the sectoral analysis sectors with higher workers bargaining power typically show higher price cost margins

periodic versus can order policies for coordinated multi item inventory systems the coordinated multi item inventory problem refers to the problem of managing inventories where there is a joint fixed cost for replenishing plus an item by item fixed cost for each item included in the replenishment order given that the optimal solution is likely to be too complex attention has focused on fixed heuristics and in particular can order or s c s policies this paper makes two contributions first a new lower bound on the cost of the optimal policy is proposed in order that the performance of heuristics may be measured second motivated by the lower bound a simple periodic policy is proposed and shown to be an improvement over can order policies for many data sets

a dynamic joint replenishment policy with auto correlated demand we consider a joint replenishment problem where the product demands are auto correlated but independent of each other a dynamic periodic review policy is developed and its parameters are determined by a heuristic which aims at minimizing the total inventory cost which includes the holding cost the set up cost and the shortage cost the heuristic updates the review interval and the target inventory level of every product at each review point based on the current inventory status and the past demand data a simulation model is developed to compare the performance of this proposed policy with an existing periodic review policy the results show that the proposed policy has consistently achieved significant saving in all the different experimental scenarios

union s threats and wage determination this paper considers local wage bargaining as a sequential game and focus es on how different rules of the game affect employment and equilibri um payment to workers and employers work to rule and other go slow t hreats lead to low employment while strike threats lead to high empl oyment an increase in the bargaining power of the union induces high er or unchanged equilibrium employment in the strike threat case whi le employment is reduced in the slow down case finally if all kinds of industrial actions are legal only one is credible which type de pends on the parameters of the model copyright 1988 by royal economic society

coordinated replenishments in a multi item inventory system with compound poisson demands in many practical applications or multi item inventory systems significant economies of scale can be exploited when coordinating replenishment orders for groups of items this paper considers a continuous review multi item inventory system with compound poisson demand processes excess demands are backlogged and each replenishment requires a lead time there is a major setup cost associated with any replenishment of the family of items and a minor item dependent setup cost when including a particular item in this replenishment moreover there are holding and penalty costs we present an algorithm which searches for a simple coordinated control rule minimizing the long run average cost per unit time subject to a service level constraint per item on the fraction of demand satisfied directly from on hand inventory this algorithm is based on a heuristic decomposition procedure and a specialized policy iteration method to solve the single item subproblems generated by the decomposition procedure the model applies to multi location inventory systems with similar cost structures for coordinated deliveries

relative wages under decentralized and corporatist bargaining systems in studying the relationship between wage inequality and centralization in collective bargaining we distinguish central from local systems of wage determination by assuming that a central union takes the employment effects of negotiated wages into account whereas unions disregard these effects in decentralized systems two different sources of wage differentials are studied separately i heterogeneous workers with different skills and ii heterogeneous firms with varying levels of economic rent per employee with respect to skill levels the impact of centralization is ambiguous whereas inter firm wage differentials are likely to be lower in corporatist systems

investment profit sharing and the degree of centralization abstract this paper examines monopoly unions which are strong enough to use two part tariffs i e basic wages plus profit shares it is shown that decentralization in bargaining increases the total pay per worker and lowers the levels of capital stock and income

an association clustering algorithm for can order policies in the joint replenishment problem abstract many studies have shown that the total cost of employing joint replenishment for correlated items is less than the total cost of using single item replenishment savings increase dramatically when the demand between items is closely related although the benefits of joint replenishment are significant it is difficult to define the demand correlation among items especially when the number of items increases a large number of items reduces the efficiency and advantage of the multi item inventory control to overcome this difficulty an association clustering algorithm this paper proposes to evaluate the correlated demands among items the proposed algorithm utilizes the support concept in association rule analysis to measure the similarity among items based on these measurements a clustering method is developed to group items with close demand in a hierarchal way the can order policy is then applied to the optimal clustering result as decided by the proposed performance index to illustrate the benefits of the proposed association clustering algorithm for replenishment systems a set of simulations and a sensitivity analysis is conducted the results of the experiments show that the proposed method outperforms several replenishment models

relative wages efficiency wages and keynesian unemployment while modern economic theorists have produced a variety of explanations for the failure of wages to fall in the face of unemployment keynes emphasis on relative wages has not been reflected in most contemporary discussions this short paper suggests that relative wage theories in which workers productivity depends primarily on their relative wage provide the best available apparatus for understanding actual unemployment and its fluctuations such theories are very closely related to the efficiency wage theories that have received widespread attention in recent years this abstract was borrowed from another version of this item

labour markets and innovation ex post bargaining abstract there is considerable interest in how labour market conditions affect innovation lying behind much of the existing work on this question is a simple model of a single union bargaining with a single firm in which in the absence of binding contracts the union reduces the returns to innovation without bearing any of the costs this misses an important feature of some rd with efficient contracts there are cases where being faced with a stronger union will help a firm to win a patent race it would otherwise have lost

efficiency wage models of unemployment keynesian economists hold it to be self evident that business cycles are characterized by involuntary unemployment but construction of a model of the cycle with involuntary unemployment faces the obvious difficulty of explaining why the labor market does not clear involuntarily unemployed people by definition want to work at less than the going wage rate why don t firms cut wages thereby increasing profits

efficiency wages and local versus central wage bargaining abstract a simple efficiency wage model is extended to allow for the presence of unions the presence of unions aggravates the unemployment caused by efficiency wage considerations provided the labour demand elasticity is not too much larger than one local firm level wage bargaining gives a higher negotiated wage than central wage bargaining implying higher unemployment under local wage bargaining than under central wage bargaining

effects of correlation on intermittent demand forecasting and stock control abstract this study investigates the effects of three different types of correlation on forecasting and stock control of intermittent demand items applying appropriate forecasting and stock control methods to theoretically generated compound poisson demand data we show that correlation in intermittent demand does play a role in forecast quality and stock control performance negative autocorrelation levels lead to higher service levels than positive values while cost does not significantly change our results also show that high intermittency levels intensify these changes in service level we also show that cross correlation produces results in the opposite direction of autocorrelation in size or intervals that is positive negative cross correlation leads to higher lower service levels

cooperation and game theoretic cost allocation in stochastic inventory models with continuous review we study cooperation strategies for companies that continuously review their inventories and face poisson demand our main goal is to analyze stable cost allocations of the joint costs these are such that any group of companies has lower costs than the individual companies if such allocations exist they provide an incentive for the companies to cooperate we consider two natural cooperation strategies i the companies jointly place an order for replenishment if their joint inventory position reaches a certain reorder level and ii the companies reorder as soon as one of them reaches its reorder level numerical experiments for two companies show that the second strategy has the lowest joint costs under this strategy the game theoretical shapley value and the distribution rule a cost allocation in which the companies share the procurement cost and each pays its own holding cost are shown to be stable cost allocations these results also hold for situations with three companies

labour markets bargaining and innovation much of the recent empirical work on the impact of unions on rd ii under some circumstances an increase in union strength can make both firms and unions worse off we survey a more recent theoretical literature which takes account of the fact that r d is often undertaken for strategic reasons by firms that are in competition with one another we show that in this framework the prevailing theoretical paradigm may be overturned thus when firms and unions can enter into long term bargains then an increase in union strength will increase decrease r d spending if successful innovation causes employment to rise respectively fall however when r d falls then this increase in union strength can cause both firms and unions to be better off when firms and unions engage in short term bargaining then an increase in union bargaining strength will cause r d to fall when bargaining is over wages alone however when bargaining takes place over wages and employment then if unions care a lot about employment the relationship between union strength and r d is inverse u shaped