Minority Game of price promotions in fast moving consumer goods markets

A variation of the Minority Game has been applied to study the timing of promotional actions at retailers in the fast moving consumer goods market. The underlying hypotheses for this work are that price promotions are more effective when fewer than average competitors do a promotion, and that a promotion strategy can be based on past sales data. The first assumption has been checked by analysing 1467 promotional actions for three products on the Dutch market (ketchup, mayonnaise and curry sauce) over a 120-week period, both on an aggregated level and on retailer chain level.

The second assumption was tested by analysing past sales data with the Minority Game. This revealed that high or low competitor promotional pressure for actual ketchup, mayonnaise, curry sauce and barbecue sauce markets is to some extent predictable up to a forecast of some 10 weeks. Whereas a random guess would be right 50% of the time, a single-agent game can predict the market with a success rate of 56% for a 6–9 week forecast. This number is the same for all four mentioned fast moving consumer markets. For a multi-agent game a larger variability in the success rate is obtained, but predictability can be as high as 65%.

Contrary to expectation, the actual market does the opposite of what game theory would predict. This points at a systematic oscillation in the market. Even though this result is not fully understood, merely observing that this trend is present in the data could lead to exploitable trading benefits. As a check, random history strings were generated from which the statistical variation in the game prediction was studied. This shows that the odds are 1:1,000,000 that the observed pattern in the market is based on coincidence.     

A game-theoretic taxonomy of social dilemmas

Both social psychology and experimental economics empirically investigate social dilemmas. However, these two disciplines sometimes use different notions for very similar scenarios. While it is irrelevant for economists whether an experimental public-good game is conceptualised as a take-some or give-some game – i.e., whether something is conceptualised as produced or extracted – it is not irrelevant for some psychologists: they grasp public-goods games as “give-some” games. And whereas most economists define social dilemmas in reference to a taxonomy of goods, some psychologists think that dominant strategies are a necessary attribute. This paper presents a taxonomy that relies on a formal game-theoretic analysis of social dilemmas, which integrates and clarifies both approaches. Because this taxonomy focuses on the underlying incentive structure, it facilitates the evaluation of experimental results from both social psychology and experimental economics.     

Optimal pricing for information goods with piracy and saturation effect

We analyze the pricing decision of a firm selling a product for which there is a significant and continuous saturation effect over time and that can be pirated. Assuming that the firm uses a skimming strategy, we solve three profit maximization models, given demand that is linearly decreasing in price. Few prices can be used over the life of the product. The effects of both piracy and saturation are combined in the first model. In the second model, the firm can invest in technology or copyright enforcement to reduce piracy. The third model describes the case in which piracy leads to increased awareness of the product and increased demand. Numerical sensitivity analysis and examples are used to illustrate the results. The results indicate that under strong piracy and saturation effects, a skimming strategy is suboptimal.     

发展中国家出口商品结构优化的战略决策非线性目标规划模型及应用

本文讨论了发展中国家出口商品结构优化的目标及对约束条件的确定，进而建立了优化出口商品结南非线性目标规划的战略决策模型，并以中间为实例进分了求解和分析，得到了我国出口商品最优结构及一些有意义的建议     

存货论模型的建立

商家进货要有计划 ,进货过多 ,卖不出去 ,造成货物积压 ,库存费增加 ;进货过少 ,供不应求 ,使销量减少 ,影响收益 .如何合理地定期进货 ,使商家获取收益最大 ,本文就存货论模型 ,利用转移概率 ,寻找最佳进货方案 ,为合理进货提供依据 .     

延期支付条件下允许缺货的变质物品库存模型

在延期支付条件下,建立了缺货量部分拖后的变质物品库存模型,证明了最优解的存在性与唯一性,并给出确定最优订购策略的算法步骤,最后用数值例子验证了模型与算法的有效性.     

部分延期付款下易腐品联合经济订货批量模型

针对易腐品供应链的联合库存决策问题展开研究.假设供应链内存在唯一的供应商和零售商,供应商提供商业信用期给零售商,但零售商需要在收到订货后,立即交付部分货款,且零售阶段由于条件限制,产品存在常数腐败率,而联合决策模型的目标是确定供应商的订货量乘数n和零售商的订货周期使得供应链的总成本最低.通过建立该问题的数学模型,证明了目标函数的性质,说明当给定n时,目标函数在每种情况下都存在唯一最优解.以此为基础,给出了相应的求解算法对该联合批量决策模型进行了求解.最后,结合运作管理实践,并通过数值算例说明了模型的有效性.     

Role of recommendation in spatial public goods games

We study the role of recommendation in a co-evolutionary public goods game in which groups can recommend their members for establishment of new relationships with individuals outside the current group according to group quality. Intriguingly, for square lattices and ER graphs there exists optimal group quality for recommendation that induces positive feedback between cooperation and recommendation. Snapshots of spatial patterns of cooperators, defectors, recommended cooperators and recommended defectors show that if group quality is appropriate for recommendation, cooperation and recommendation can simultaneously emerge. Moreover, we find that local recommendation improves cooperation more than global recommendation. As an extension, we also present results for Barabási–Albert networks. The positive effect of recommendation on cooperation for Barabási–Albert networks is independent of group quality. Our results provide an insight into the evolution of cooperation in real social systems.     

等级信用支付策略下变质性产品的库存优化模型

基于两层次和等级信用支付策略构建了变质性产品的库存模型,即模型假设上游供应商给予下游零售商一个固定的信用支付期,同时零售商对客户实施带有等级区别的信用支付策略。零售商给予信用好的客户全额贸易信贷且不需要任何押金,相反对信用不好的客户不给予贸易信贷的优惠。讨论了模型最优解的存在性与唯一性,并提供了寻求系统最优订货策略的简单方法。最后,给出了具体数值算例和主要参数的灵敏度分析。