Assortative Matching and Search

In Becker's (1973) neoclassical marriage market model, matching is positively assortaive if types are complements: i.e., match output f(x, y) is supermodular in x and y. We reprise this famous result assuming time‐intensive partner search and transferable output. We prove existence of a search equilibrium with a continuum of types, and then characterize matching. After showing that Becker's conditions on match output no longer suffice for assortative matching, we find sufficient conditions valid for any search frictions and type distribution: supermodularity not only of output f, but also of log f_x and log f_xy. Symmetric submodularity conditions imply negatively assortative matching. Examples show these conditions are necessary.     

Directed Matching and Monetary Exchange

We develop a model of monetary exchange where, as in the random matching literature, agents trade bilaterally and not through centralized markets. Rather than assuming they match exogenously and at random, however, we determine who meets whom as part of the equilibrium. We show how to formalize this process of directed matching in dynamic models with double coincidence problems, and present several examples and applications that illustrate how the approach can be used in monetary theory. Some of our results are similar to those in the random matching literature; others differ significantly.     

电商平台信息披露策略研究

电商平台模式下，供应商决定产品价格将产品直接出售给消费者，并与平台企业共享收益。通常，消费者与产品供应商/平台企业在产品属性(匹配)信息上存在不对称性。本文基于博弈理论，研究电商平台(如：亚马逊、京东等)的产品信息披露策略，比较两种信息披露方式：“平台披露”与“供应商披露”。首先考虑由一个平台企业和一个供应商组成的垄断结构。研究表明，信息披露策略取决于产品属性(匹配)的相对重要性。同时，与平台披露相比，供应商更愿意披露全部产品信息。然后考虑一个平台企业和两个供应商组成的竞争结构。研究发现，与垄断结构不同，平台披露下，平台总是披露全部产品信息；而供应商披露下，信息披露策略取决于产品属性(匹配)信息的相对价值。此外，平台会偏好由供应商负责信息披露。     

From a spontaneous community of practice to a piloted community of practice: A longitudinal study of resilience construction

The article focuses on piloted communities of practice (PCoPs), which have evolved significantly in recent years in the knowledge-based economy. These social structures represent real difficulties in terms of management, particularly with regard to the possibility of reconciling two apparently contradictory logics, self-organization and control. Although recent empirical work in the literature provides a general picture of these PCoPs, they do not provide details of how this piloting is implemented over the long term. This paper uses a flexible pattern matching approach on a longitudinal case study to analyze the shift from a spontaneous community to a piloted community. The community studied here is the sound engineers of Radio France. The results highlight that piloting can only be relevant if it is presented as a reification process that makes sense to those involved. The study also emphasizes that self-organization and control can be harmonized through the creation of an ad hoc structure and that some PCoPs can be ambidextrous. In this study, we underline in which conditions the piloted community allows to maintain the resilience of an organization.     

基于压缩感知的智能天线DO A估计算法

波达方向（direction of arrival，DOA）估计是利用具有一定空间结构的天线阵元对空间信源的来波方向进行估计。为解决MUSIC算法和ESPRIT算法在智能天线DOA估计中空间谱分辨率和抗噪声性能方面的不足，依据压缩感知理论的贪婪算法思想，将匹配追踪（matching pursuit，MP）算法和子空间追踪（subspace pursuit，SP）算法应用在DOA估计中，即提出2种新的算法MP-DOA和SP-DOA。这2种算法主要包括原子库建立、信号投影、最佳匹配原子筛选及信号特征提取等过程。4种算法的仿真实验与对比分析结果表明，MP-DOA算法在低信噪比情况下较其他3种算法性能更优越，SP-DOA算法在角度分辨率和对信源数的包容方面的性能较其他3种算法优越，也验证了应用压缩感知理论的优越性。     

On the Failure of the Bootstrap for Matching Estimators

Matching estimators are widely used in empirical economics for the evaluation of programs or treatments. Researchers using matching methods often apply the bootstrap to calculate the standard errors. However, no formal justification has been provided for the use of the bootstrap in this setting. In this article, we show that the standard bootstrap is, in general, not valid for matching estimators, even in the simple case with a single continuous covariate where the estimator is root‐N consistent and asymptotically normally distributed with zero asymptotic bias. Valid inferential methods in this setting are the analytic asymptotic variance estimator of Abadie and Imbens (2006a) as well as certain modifications of the standard bootstrap, like the subsampling methods in Politis and Romano (1994).