American Journal of Operations Research, 2012, 2, 59-72 http://dx.doi.org/10.4236/ajor.2012.21007 Published Online March 2012 (http://www.SciRP.org/journal/ajor) Who Benefits from Altruism in Supply Chain Management? Zehui Ge1, Qiying Hu2 1Business School, University of Shanghai for Science and Technology, Shanghai, China 2School of Management, Fudan University, Shanghai, China Email: [email protected], [email protected] Received September 9, 2011; revised October 12, 2011; accepted October 22, 2011 ABSTRACT The significant effect of social preference on strategic behavior has been convinced by recent research. Along this stream of research, we study firms’ altruistic incentives in supply chains since the selfish rationality can’t deal with economic behaviors. We show that the performance of the supply chain in consideration of altruism is between those of scenarios under decentralization and under integration. We further shows that a manufacturer, as a leader, should find an egoistic retailer, while a retailer, as a follower, should find a manufacturer with altruistic liability, to form a good chain. Keywords: Supply Chain Management; Coopetition; Altruistic Preference; Advertising/Sales Effort; Pricing 1. Introduction which combines pricing and inventory control. Reference [5] investigates the effects of risk aversion on the price A great deal of attention has been paid to supply chain and order quantity. Furthermore, [6] studies a joint pric- management (SCM) in the last decades, in which supply ing/inventory game of multiple newsvendors under com- chain coordination is mainly discussed due to double petitive situations. marginalization in decentralized chains. However, the Besides pricing, firms often use advertising/sales effort wholesale-price contract is commonly adopted by man- to spur demand. This plays a key role in managing mar- agers in practice, even though the literature has shown keting-operations interface. In considering the dimension that it cannot coordinate the supply chain. Recently, of sales effort, [7] models a simultaneous choice of sales some researchers try to explain this phenomenon (eg. [1]). effort and order quantities in a newsvendor environment. Based on a generalized newsvendor model, this paper In considering the dimension of advertisement, there is investigates the coexistence of competition and coopera- also a huge collection of literature regarding various tion in a supply chain where pricing, ordering, and ad- kinds of advertising. For instance, [8] link advertising to vertising/sales effort (henceforth ASE) are considered quantity decision in a newsvendor setting. While [9] dis- simultaneously. Another, we introduce social preferences cusses optimal pricing and advertising in a durable good into decision maker’s utility to study cooperation in the duopoly, and [10] considers brand name advertising into supply chain. demand identification. There are three streams of research related to our paper. The second stream related to our research is SCM with In the following, we briefly review the most related re- stochastic demand. Along this direction, the classic search and describe our contributions with respect to the newsvendor model is also extended to include the inter- vast, growing literature (See Figure 1 for a sketch). face (contract) of a firm with its upstream suppliers. The First, the newsvendor model is the most basic model in most prevalent contract in practice is the wholesale price- SCM, where a retailer faces a random demand in a single only type, which involves the newsvendor paying a per- period and must decide how many units of the product to unit wholesale price charged by the manufacturer. Ref- stock before the demand is realized (see [2]). Reference erence [11] gives a complete analysis of this model under [3] is the first to incorporate pricing into the newsvendor demand distributions with increasing generalized failure model by assuming that demand rate depends linearly on rate (IGFR). The wholesale-price contract does not coor- price. Following Whitin, the newsvendor problem has dinate the supply chain (see [12]), unless such social been extended by many other researchers. Reference [4] preferences as fairness are taken into consideration (e.g., provides a significant review in the direction of research [1]). Copyright © 2012 SciRes. AJOR 60 Z. H. GE ET AL. demand under asymmetric information structure. He et al. focus on how to coordinate a decentralized supply chain, where the retailer’s sales effort, order quantity, and retail price are involved in a random demand setting ([22]). In light of the first and second streams of research, our first objective is to apply further consideration to the manu- facturer’s advertising efforts and focus on determining solutions for the decentralized supply chain. The third stream related to our research entails evalu- ating firms’ utilities in SCM. Such evaluations are related to decision-making patterns of SCM. Specifically, there are two main patterns in the current literature. One is the decentralized supply chain in which each member makes decisions to optimize its own objective. The other pattern is the centralized supply chain in which all decisions are jointly made to maximize the total profit of all members. Usually, the centralized chain is a benchmark for the decentralized one. One can see these patterns in [23], or Figure 1. The position of our research. A: the classical news- [13]. vendor problem, e.g., [2]; B: a supply chain with wholesale- However, firms in a chain form a relative loose verti- price only payment, e.g., [11]; C: utility rationalizations or decision making patterns, e.g., [23]; D: ordering + pricing cal relationship ([24]). The supply chain may encounter a for a newsvendor, e.g., [4]; E: ordering + ASE for a news- significant loss in efficiency because of the loose rela- vendor, e.g., [7,8]; F: ordering + pricing for a supply chain, tionship without contractual constraints. Therefore, mem- e.g., [14]; G: ordering + ASE for a supply chain, e.g., [17]; bers in a supply chain need to coordinate their decisions H: a decentralized supply chain (competition), e.g., [13]; I: a to improve the chain’s efficiency. In fact, seldom do centralized supply chain (cooperation), e.g., [23]; J: coopeti- successful firms in SCM take selfish actions to maximize tion, e.g., [28]; K: ordering + pricing + ASE for a supply chain in the newsvendor setting, e.g., [22], this paper; L: their own profits while leaving their partners out to dry. coopetition in consideration of altruism, this paper. There are plenty of studies on competitive scenarios that highlight this phenomenon, e.g., [25,26]. As with the newsvendor model, other decisions are In practice, cooperative and competitive incentives considered in SCM. By combining pricing, [13] analyzes generally coexist. This phenomenon is referred to as the competition in a decentralized supply chain, and [2] “coopetition” ([27]). Coopetition is still an under-re- presents a newsvendor pricing game in which there exist searched theme in SCM, even though it has been invest- a single manufacturer and multiple retailers. Syntheti- tigated by several studies from the perspective of invent- cally, [14] presents an extensive review of coordinated tory management. For instance, [28] develops a general pricing and production decisions by classifying the ex- framework for analyzing decentralized distribution sys- isting models along two dimensions: deterministic versus tems with sequential decisions of inventory and alloca- stochastic, and static versus dynamic. Another review tion. In their model, ordering decisions of different re- can be seen in [15], etc. tailers are assumed to be made independently/compete- Nevertheless, the supply chain system can increase the tively, while allocation or transshipment decisions are total business “pie” by ASE. For instance, [16] examines assumed to be made cooperatively. A common focus of coordinating contracts of a decentralized supply chain in these studies is on firms’ decision-making, but not on which the retailer can choose promotional effort. For a rationalization of firms’ utilities. channel rebate contract, [17] employs a simple model in On the other hand, there is sufficient evidence that which a retailer makes ordering and effort decisions and firms care about their partners’ profits as well as their then observes demand. Furthermore, [18] investigates the own in order to improve the competitiveness of the total impact of the retailer’s sales effort on the manufacturer’s supply chain. It is well known that the chain’s overall sale-timing decision, in which the payment to the manu- strength benefits each member. A live case comes from a facturer depends on the retailer’s order quantity. In re- global executives talk published in Harvard Business lated research, Z. Huang and his cooperators, e.g., [19,20] Review (see [29]) where A. B. Cummings, the president study cooperative advertising in a supply chain with and COO of the Coca-Cola’s Africa Group, recounts one price independent/dependent demand. In the above re- of his successful altruistic decisions. In order to increase search, the demand is deterministic. Reference [21] stud- their bottlers’ profits, Cummings increased the retail ies cooperative advertising model with a price dependent price, which resulted in increased system profitability Copyright © 2012 SciRes. AJOR Z. H. GE ET AL. 61 after six months for both bottlers and the Coca-Cola p is a base price-demand function, s0 indicates Company itself. From a biological viewpoint, [30] con- the effort effectiveness associated with the brand name ducts experiments to show how the human brain limits advertising, and t 0 with local sales effort. Moreover, the impact of selfish motives and implements fair behav- asat is assumed to be concave in both a and a , m r m r ior. [31,32] also find that altruism is a gene-culture co- which implies that (the deterministic portion of) the de- evolution and an internalization of norms. In the context mand increases with both types of effort, but at a dimin- of SCM, [33-37] discuss the effect of altruism on strate- ishing rate. in Equation (1) is a random variable in gic behavior or partnership management. Differently A,B0, with the probability density function with these papers, we consider altruism in a generalized f and cumulative distribution function F. supply chain with such decisions as ordering, pricing and Let qdp,a ,a represent a stocking factor, m r ASE. Furthermore, our findings point out who should which describes the gap between the order quantity and answers more for a good vertical partnership. the deterministic portion of the demand. After the ran- Based on altruistic phenomena occurring independ- dom part of the demand is realized, if it exceeds , we ently of contract machines, our second objective is to say there occurs stocking shortage, otherwise, stocking study firms’ behavior in a cooperative supply chain. We residue. The expected sale quantity of the retailer is study coopetition in a generalized newsvendor setting, Eminq,DqFd which includes three kinds of simultaneous decisions: A price (both wholesale price and retail price), order quan- pasat Fd. tity, and ASE. To some extent, the wholesale pricing is m r A for competition while ASE for cooperation. At the same Therefore, the retailer’s expected profit is time, we interpret firms’ cooperative incentive as their π w,p,q,a ,a pEminq,Dwc qa r m r r r altruism, and introduce altruistic preferences to charac- (2) terize firms in the supply chain. We study firms’ deci- pwc q pFxdxa , r A r sions in three supply chain scenarios: integration, decen- and the profit of the manufacturer is tralization, and coopetition. Also, we analyze the impact of firms’ altruistic preferences on performance of the π w,a ,qwc qa . (3) m m m m supply chain through numerical analysis. The total profit of the supply chain, defined as the sum The rest of the paper is organized as follows. In Sec- of those of the manufacturer and the retailer, is tion 2 we present our model. Section 3 shows the exis- tence of Nash equilibrium and compares three scenarios. π p,q,a ,a s m r We further present the effects of altruistic preference on π w,a ,qπ w,a ,q,p,a (4) decision-making by numerical analysis in Section 4. Fi- m m r m r nally, Section 5 concludes this paper. pc c q pFxdxa a . m r A m r 2. Model For convenience, we abbreviate their profits as πr, π , π , respectively. m s The supply chain considered here consists of one retailer Without loss of generality, we assume p ranges from and one manufacturer. As usual in the literature, the c c to an upper bound p. Obviously, the retailer will mr manufacturer (denoted by M) acts as a leader, and the set pwc so as to get a positive profit. The fol- r retailer (denoted by R) follows. For a type of product lowing proposition presents the scope of the stocking supplied, the manufacturer firstly offers a wholesale factor . price w and a brand name advertising level a . As a Proposition 1 The stocking factor always falls m response, the retailer orders q units and retails them at into the support set of , i.e., A,B. price p per unit. At the same time, he decides his sales All the proofs see Appendix. Now, we make the fol- effort level a . The stochastic demand faced by the re- lowing assumption for our model. r tailer depends on a , a , and p. Unmet demand is lost. Assumption 1 p is twice differentiable, and sat- m r The unit producing cost is c , and the retailing one is isfies: 1) p0andp0, and 2) c . It is convenient to assume mthat the unit costs c and 2p2pp0. r m c are constants, since our purpose is to examine basic The twice differentiability above is merely for con- r properties of altruism in SCM. venience, for it simplifies our description. Item 1) above The demand is as follows, indicates that the retailer faces a downward sloping and nonnegative base demand curve. Item 2) above is en- Ddp,a ,a pasat . (1) m r m r sured by the concavity of p. Since it can be written Here dp,a ,a is the deterministic portion, where as p2p2 p when the demand is convex, m r Copyright © 2012 SciRes. AJOR 62 Z. H. GE ET AL. it indicates that the degree of convexity is not too large since firms reasonably care about their own profits more for any given p. Certainly, it holds when the demand is than that of others. The larger the altruistic preference, concave. By examination, we find that Assumption 1 is the more altruistic the firm will be. true for most demand functions (e.g., exponential de- The decision mechanism here is exactly as that in the mand pep and linear demand pp scenario (DS). That is, first the manufacturer chooses w for 0, power demand pp with 1). and a , and then the retailer decides p, q, and a . m r Hence, the coopetition of the supply chain (denoted by 2.1. Integrated Supply Chain CS) can be formulated as For the integrated supply chain (IS), both the manufac- Stage 1: maxU m turer and the retailer belong to the same enterprise with w,am (DS) Stage 2: maxU the total profit π . Thus, the problem is to maximize π r s s p,q,ar by choosing a ,q,p and a : m r Clearly, (DS) is a special case of (CS). max π pc c q pFxdxa a . (IS) We use superscripts D, C, and I to designate three am,q,p,ar s m r A m r scenarios in this paper, (DS), (CS) and (IS), respectively. For uniform symbol definition, π will be rewritten Remark 1 s as U in the remainder. 1) Another interpretation of Equation (5) is that each s firm wants to maximize the weighted sum of his/her own 2.2. Decentralized Supply Chain profit and the chain’s profit. Then, the utility of the manufacturer is π 1π π π 1π In the decentralized supply chain (DS) the manufacturer, m m r m r for any given parameter , which means 1. as a leader, chooses her wholesale price w and brand m The same with the retailer. name advertising level a . Then the retailer chooses the m 2) It should be noted that U U U when both order quantity q, sales effort level a , and retailing price m s r r and approach to 1, but (CS) here is not the in- p as his response. They both want to maximize her/his m r tegrated scenario, since (CS) is still a decentralized sys- own expected profit by playing a Stackelberg game as tem with the manufacturer and the retailer as its two de- follows, cision makers. However, this should be studied using a Stage 1: maxπ , different method. Hence, we do not give much attention m w,am (DS) to it in this paper. Stage 2: maxπ . r p,q,ar 3. Nash Equilibrium This will be solved by the backward method in the next section. In this section, we solve the three scenarios. Before doing this, we first make some preparations. 2.3. Coopetitive Supply Chain 3.1. Some Preparations In the literature of SCM, it is assumed that all members in the supply chain exclusively pursue their own profits We will introduce two functions p and M p w w and do not care about “social” goals per se. As we have in this subsection. For the first function p, we con- w explained in the Introduction, firms may care about oth- sider a basic decentralized setting where ers’ profits in order to enhance the system’s compete- 1) both effort levels a and a are exogenous, i.e., m r tiveness. Certainly, they still pursue their own profits at constant; and the same time. That is, they may be both egoistic and 2) the demand is deterministic, i.e., 0. altruistic. When making decisions, each firm may trade So we can assume that the demand is off its own profit together with their partner’s profit. For Ddpp. This basic setting will be used to this, we introduce altruistic preferences and for compare our results with those in the literature. m r the manufacturer and the retailer, respectively. Since the supply chain is decentralized, we can get the In this paper, we model altruistic preferences in firms’ following result when qp (it is essential to as- utilities by adopting a weighted summing formulation. sume a a 1) m r This mean the utilities of the manufacturer and the re- π w,p,q,1,1 pEminq,pwc q tailer are, respectively, r r pwc pwc qp U π π , r r Umπmmπ r. (5) pwc pπ w,p,p,1,1. r r r m r r It is assumed that both and belong to [0,1), Similarly, we still have the same result when m r Copyright © 2012 SciRes. AJOR Z. H. GE ET AL. 63 qp. Therefore, it is optimal for the retailer to order lowing condition that an optimal price must satisfy: qp for any given w and p. Then the retailer’s profit (denoted by p) in the basic decentralized set- 0q ppamsartF()AFd ting is pπ w,p,p 1cm p1ttss pppcm cr w pr wc p, (6) F1pcmcr pFdA r A pwcr. 1 p1ttss pF1pcmcr pFdA cm cm A The following proposition shows the existence and M p. uniqueness of the optimal retail price in this basic setting. cm Proposition 2 There exists a unique optimal retail (10) price p* at which p is maximized. Hence, the solution of Equation (8) can be found by w w The second function is defined by solving Equation (10), which includes only one variable p. Actually, M p represents the marginal profit of M p AF1pwcr pFd the integrated sucmpply chain on the retail price whenever w A the other decision variables change with p according to ts 12awm1stpw1(tps1twtpw,p w wccmm, (7) p(9r)oT.f ihHt eeoorfre (eaIfmSte) .r1 ,T wUheins d cseahrlol owpMst itcmhmea lfpiotyll ofaownri na(IguS gt)mh, eteohnrete emodp .m ti maragli nrae-l tail price satisfies M p0, and a , a , and q are 1 t cm m r for any wc , where 1 sstt1ts and 2 t1t determined by Equation (9). m From the theorem above we know decision-making in are two constants determined by s and t, and (IS) can be realized by solving M p0. Thus, it is F1F. The meaning of Mwp will be given important to judge the sign of M cmp for any given p. in the following subsection. Here, we get one proposition cm finrogTPm hr Moeth pwemo sciipontniiomt inniu num3 i t Tycoh mofe fr eMc Mmrw,wupsptp .e ,x .i is. te .a, pMricwe ppw**w** , mwinililm ibze- iaNnno dLRtwh eee mmwp bc*meem*am safui bcre 1tpdrh c*iemencrMg ed wnctimhtshrcaeautnlp isezsvpe esdc*mor 0 sm e iMetsft oipctnmrhrg oe,p a prLelce*lrm*e ttamieiplmse r0oa’f s. 1 co Mmepstctimamcbral,pilsp hpc*.mer is c ae, used to judge whether the Nash equilibrium exists in the comparison of p* with the minimizer of M p. following subsections. cm cm When the augmented marginal profit in (IS) is non-posi- 3.2. Optimal Solutions of (IS) tive, i.e., Mcm p0, the supply chain has no incentive to further increase the retail price. In fact the chain will In this subsection, we get optimal solutions for scenario drop the retail price in order to increase its profit. Then, (IS). Its first-order condition is obviously as follows, the optimal retail price (denoted by pI ) in (IS) should U pq ppasatFFd0, be larger than the basic decentralized pricing pc*m, as s m r A shown in the following theorem, where the existence of U q pFc c 0, the optimal solution for (IS) is proved. In the theorem, s m r (8) we denote by Npp,qp,a p,a p the solu- U a sppas1atF10, m r s m m r tion induced by the retail price p for (IS) via Equation Us ar tppamsart1F10. (9). Theorem 2 For (IS), there must exist an optimal solu- By using some mathematic technologies we can get tion pI,qI,aI,aI. Moreover, am, ar, and q, as functions of p as follows. 1) if M pm**r0 then there is an interior solution a1rts sst1scm p pI pc*m,cpmc*m*c msatisfying am 1cm p11ts (9) McmpcIm0,Mcm pcIm0. (11) ts Furthermore, for any pI c c ,p satisfying Eq- q1pcm p1ts F1pwcr p uation (11), NpI must be a mlocalr optimal solution of (IS); We write as ap , a p, and qp when nec- m r 2) If M p**0, the optimal solution is Np; essary. Substituting the above three equations into the cm cm first equation in (8) and rearranging it, we get the fol- 3) If M p**0, the optimal solution is either cm cm Copyright © 2012 SciRes. AJOR 64 Z. H. GE ET AL. Np** or Np. and a of the manufacturer. cm The mfirst-order condition for the retailer is We make no direct restriction on the distribution func- otiuorn imFport,a ntht oreusguhl tist ims tahya ti nthfleu eonpctiem aMl rcemtaiplc *m*pri.c eO inne ( IoSf ) Us pq ppamsartFAFd0, is larger than the one obtained in the basic decentralized U q pFwc wc 0, (12) s r r m setting; i.e., pI p* . This result comes from our in- corporating with unccemrtainty demand and ASE, since the Us ar tppamsart1F10. retailer sets a higher price so as to mitigate the effects of uncertainty and promoting effort. Similar to (9), we get The second result in Theorem 2 refers to such a non- a1t tas p normal market in which the augmented marginal profit is r m w always positive, no matter how high the retailing price is. s t (13) In this type of market, the retailer will set p to be the up- q2am1tpwp1t F1pwcr p per bound p. When p is sufficiently large, it is obvi- ous that Npp,B,0,0 in this time. That is, the where wwrwcm . Substituting (13) into the first equation in (12), we obtain retailer will order a quantity of B, and the deterministic pstaorct koefd tohnel yd efmora nmda tacphpinroga tchhee ss ttooc hzaesrtoic, aplal rtB o uf ntihtes daree- 2a1st p1tt pF1pwcr pFdA m w w A (14) mand. Furthermore, both manufacturer and retailer need M p0. no advertising/sales efforts. Such a case is the contingent w market, where almost all inventories meet emergencies, There exist solutions of Equation set (12) as long as and then retailers are inclined to bid up price. Therefore, Equation (14) has roots. Thus, the existence of an opti- this type of market would be better to be supervised by mal response from the retailer can be obtained by solving the government (e.g., a market of such products against M p0. Then, similar to Theorem 2, we have the food crisis). w following result about the retailer’s optimal response in From the proof of Theorem 2 we know that if the scenario (CS). Here, we denote by NRpp,qp, tMhec mfollpowin0g cthoeronl lapry . would not be optimal. This shows amp,arp the solution of the retailer induced from p. Corollary 1 If M p0 and Equation (11) has a unique interior soluticomn pI cm cr,p, then NpI pThwe,oarem,q 3 wTh,aere ,maustw e,xaist an fooprt itmhea lr reetaspiloenr sien ( CS), is the unique optimal solution of (IS). m m r m provided with wc and a 0. Moreover, Moreover, we present a sufficient condition to ensure 1) if M p**0m then thmere is an interior solution the uniqueness of solutions for Equation (11). pCp* wc ,wp** satisfying Proposition 4 If M p0 is downwards unimo- w r w dal, Equation (11) has ac munique solution in c c ,p. m r M pC0,M pC0. (15) The proof of the proposition is obvious. w w Remark 2 A given function is downwards (upwards) Furthermore NRpC must be a local optimal re- unimodal in an interval a,b, if and only if it has the sponse of the retailer; unique minimal (maximal) point x* and is monotone on 2) If M p**0 then the retailer’s optimal re- either side of x* in the interval (see e.g., [38]). In the w w sponse is either NRp or NRwc ; following two special cases, the downwards unimodality 3) If M p**0 then the retailrer’s optimal re- of M p is clear. w w cm sponse is NRp**, NRwc , or NRp. 1) The stochastic portion in the demand follows a w r uniform distribution on A,B. Theorem 3 gives the retailer’s optimal response to the 2) The deterministic demand is linear in p, i.e., manufacturer. Thus p, q, and a are functions of w and r pQkp, where Q and k are constants and a , respectively. A sufficient condition to guarantee the m pc c ,Q k. In fact, one can examine that M p uniqueness of these response functions is that M p is incremasinrg in pc c ,Q k when ts0.5. cTmhen, is unimodal. Substituting the functions into the manwufac- m r it is easy to conclude that M p is downwards uni- turer’s utility yields cm modal. U w,a U w,a ,qw,a ,pw,a ,a w,a m m m m m m r m 3.3. Nash Equilibriums of (CS) π w,a w,a , m m m r m First we consider the retailer’s response provided with w The first-order condition for the manufacturer is Copyright © 2012 SciRes. AJOR Z. H. GE ET AL. 65 1mrwcmq w1mq0, (16) Table 1. Nash equilibria and profits when s = 0.15, t = 0.1. 1mrwcmq am1msar tam0. S m r w p q Therefore, we can obtain the manufacturer’s best re- (IS) - - - 9.202 10.756 sponse according to Equation (16). (DS) 0 0 7.349 11.790 4.386 3.4. Comparison of Scenarios (CS) 3/7 0 5.744 11.011 6.043 In this subsection, we compare retailer’s order quantities (CS) 0 1/4 9.137 11.785 4.626 given the three scenarios. Denote the solutions in (DS), (CS), (IS), as wD,aD,pD,qD,aD, wC,aC,pC,qC,aC, (CS) 2/3 1/4 5.822 10.583 7.172 m r m r and wI,aI,pI,qI,aI, respectively. The following theo- S a a π π π m r m r m r s rem compares the order quantities. (IS) 8.967 5.974 - - 47.648 Theorem 4 For the order quantities in the three sce- narios, we have qI qC qD. (DS) 3.727 1.391 19.734 13.076 32.810 From the theorem above, cooperative incentives in- (CS) 5.103 2.369 17.522 22.284 39.806 crease the retailer’s order quantity (vs. scenario (DS)). On the other hand, the order quantity in (CS) may be (CS) 5.229 1.469 27.789 5.531 33.320 lower than that in (IS) because of the existence of the (CS) 6.710 3.105 20.700 22.342 43.042 competitive incentives. Thus, the coexistence of compe- tition and cooperation makes firms’ decisions inconsis- observation above further illustrates not only this fact, tent with those in (IS) or (DS), just between those of (IS) but also all the other decisions and profits of the chain. and (DS). Figures 2-5 and Figures 6-9 show changes of deci- sions and profits, respectively, with the altruistic prefer- 3.5. Effects of the Altruistic Preferences on ences. From Figures 2, 3, and 6, 7, we find that for any Decisions and Profits given , there is a switching level, denoted by * for m r This section gives some meaningful observations by the retailer, such that when * is large enough, an r r analyzing numerical results. Especially, we focus on the altruistic retailer sets his optimal price as low as possible, effects of the altruistic preferences on decisions and that is, pC wC c under the constraint pwC c . r r profits in (CS) (certainly, including (DS) as a special As a follower in the game, the retailer in this circum- case). We assume the base price-demand function p stance benefits nothing from the selling, but has to suffer to be linear, that is, pQkp for some positive from the effort and demand uncertainty, and thus has a constants Q and k. Surely, the domain of the retail price negative profit, due to being too altruistic. Similarly, is 0 pQ k . Furthermore, it is assumed that from Figures 8 and 9, the manufacturer has negative follows an exponential distribution with rate of , i.e. profit if she is very altruistic ( * for some * , m m m f e when 0; otherwise f 0. Let which is near 1). We call this phenomenon “doing for c 2, c 1, 1, Q15, k 1. others”. Moreover, the switching level for the manufac- m r Table 1 gives some numerical results under s0.15, turer is higher than that for the retailer, which implies t0.1, in which the values of (DS) corresponds to a that the retailer is more likely to suffer from being too classical scenario presented in the previous literature in altruistic than the manufacturer. This may be due to the Figure 1. By comparing the Nash equilibria and profits manufacturer’s first-mover advantage. for (IS), (DS), and (CS) given in the table, we find a rea- From the switching level in Figure 3, we know that as sonable explanation why decisions diverge in reality, retailer’s altruistic preference 0,* increases, so r r which is just our main contribution. Moreover, we get the does the wholesale price w and the retail price p, causing following interesting observations different with those in demand to decrease along with the retailer’s order quan- the current literature. tity q and effort a . But when the retailer is too altruistic r Observation 1 Among three scenarios, (IS) has the with *, he is “doing for others”. So, both w and p r r highest chain’s profit, order quantity, advertising, sales decrease, and the demand increases along with q and a . r effort level, and the lowest retail price; Conversely, (DS) This switching becomes more serious as the manufac- has the lowest chain’s profit, order quantity, advertising, turer’s altruistic preference increases. In fact, when m sales effort level, and the highest retail price; And (CS) is 0, q and a increase a little in * (Figure m r r r between (IS) and (DS). 2). We have shown in Theorem 4 that the order quantity On the other hand, it can be seen from Figures 4 and 5 under (CS) is between those of (IS) and (DS). Now, the that the effect of the manufacturer’s on decisions is m Copyright © 2012 SciRes. AJOR 66 Z. H. GE ET AL. Figure 2. Decision shift with η. Figure 5. Decision shift with η . r m Figure 3. Decision shift with η. Figure 6. Profit shift with η. r r Figure 4. Decision shift with η . Figure 7. Profit shift with η. m r Copyright © 2012 SciRes. AJOR Z. H. GE ET AL. 67 truistic preferences affect the profits of the manufacturer, the retailer, and the system. In general, firms are willing to benefit their partner only when they face positive prof- its. Then, our analysis in the following focuses on the normal circumstance in which both firms have positive profits and so have incentives to participate (especially, * and *). However, firms should not be m m r r too altruistic, i.e., their altruistic preferences should not be too great. Hence, it is reasonable to limit our discus- sion below in * and *. m m r r First, from Figures 6-7, one can find that the profits of the retailer and the supply chain decrease with but r that of the manufacturer increases in the region where both firms have positive profits. However, Figures 8-9 show the inverse result. The above observation is also to say that the profits of both the manufacturer and the retailer decrease with their Figure 8. Profit shift with η. r own altruistic preference, but increase with the other’s preference. That is, π 0,π 0,i, jm,r,i j. i i i i Moreover, the profit of the supply chain decreases with and increases with , i.e., r m π 0,π 0. s r s m This implies that with change of the altruistic prefer- ences, the retailer’s and the chain’s profits change in the same direction, while the manufacturer’s profit changes in the reverse direction. By classifying the members as egoistic liability (when his/her altruistic preference is low, henceforth, E) or al- truistic liability (when his/her altruistic preference is high, henceforth, A), we divide supply chains into the follow- ing four types where M and R represents the manufac- turer and the retailer, respectively. Figure 9. Profit shift with η. r AA AE (Altruistic M, Altruistic R) (Altruistic M, Egoistic R) very regular and simple: with increase of , both m prices w and p decrease while other decisions q, a , and EA EE r a increase. This surely benefits the supply chain (see (Egoistic M, Altruistic R) (Egoistic M, Egoistic R) m Figures 8 and 9). Among all decisions, the retail price p is the weakest For example, type AA represents supply chains where one affected by altruistic preferences, while the whole- both the manufacturer and the retailer have altruistic li- sale price w is the most seriously affected. One possible abilities, and Type AE represents supply chains where interpretation of this is that the retail price is mainly de- the manufacturer has altruistic liability but the retailer termined by the market, other than by type of supply has egoistic liability. Then, we get the following obser- chain, while w directly reflects the profit allocation be- vation for comparing the four types from the monotone tween the retailer and the manufacturer. properties of the profits discussed above. By comparing Figures 2 and 3 with Figures 4 and 5, Observation 2 The supply chain with Type AE is the we find that an altruistic manufacturer will lead to high best for both the system and the retailer, while the supply qC,aC,aC, and low wC, and also to high profits for chain with Type EA is the best for the manufacturer. m r the retailer and the supply chain. As for the type of re- It is intuitive that either the manufacturer or the retailer tailer, its influence is not serious. may be damaged from being too altruistic, if his/her In the following, we focus our attention on how the al- partner is too selfish. But it is interesting to discover that Copyright © 2012 SciRes. AJOR 68 Z. H. GE ET AL. the chain will be damaged from an altruistic retailer but With this, each firm considers not only his own profit but benefited from an altruistic manufacturer. also the partner’s one when making decisions. We further observe from Figures 6-9 that in compare- One of our important finds is that all the decisions and son to , the effect of on π and π is more performance in the supply chain of the coopetitive sce- m r m r serious but the effect on π is less serious. In a word, nario are between those of the other two scenarios. An- s the profits of both firms change with more sharply other important find is that a supply chain will benefit r than with ; while π increases more sharply with when the manufacturer is altruistic, having concern for m s . Especially, when the manufacturer is not too altruis- the total profit of the supply chain, and the retailer is m tic, e.g., 0.2 when 0 or 0.2 when egoistic, only having concern for himself. This find may m r m 3 7, the increase of would not reduce her own benefit firms in finding a suitable partner to form a good r m profit but increase both the retailer and the chain’ profits. supply chain (i.e., with larger profit). But if the retailer increases his altruistic preference a However, we have not obtained enough analytical re- little, he has to suffer a significant loss and so does the sults on the effect of altruistic preferences on the firms’ chain. Thus, we have the following observation. decisions and profits. This may be left for further re- Observation 3 A manufacturer with altruistic liability search, though it may prove to be quite challenging. An- will benefit both the supply chain and the retailer but other area for further research is to consider multiplica- would not hurt herself, while a retailer with altruistic tive demand. Finally, it is interesting to consider the al- liability will hurt both himself and the supply chain. truistic preferences in other models for supply chain By summarizing the above discussions, we present the management. following proposition. 5. Acknowledgements Proposition 5 In order to form a good supply chain with one manufacturer (as the leader) and one retailer We would like to thank Yusen Xia, seminar participants (as the follower), a manufacturer should find an egoistic at the Fudan university for thoughtful comments. The retailer, while a retailer should find a manufacturer who project is supported in part by the National Natural Sci- has altruistic liability. ence Foundation of China through grant 71101092 and One main insight of this paper is given in the proposi- 70832002, Shanghai Leading Academic Discipline Pro- tion above. That is, the manufacturer, as the leader of the ject (Number B210, S30501), Doctoral Fund of Ministry game, should be in charge of the supply chain. This im- of Education of China (20113120120012), and Shanghai plies that she should consider not only her own profit but Innovation Fund (11YS122). also the retailer’s profit, i.e., the profit of the whole sup- ply chain. 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