“Irregular” African migrants and asylum seekers heading to Europe mainly choose the so‐called Central Mediterranean Route (CMR) from Libya to Italy or Malta or the Western Mediterranean Route from Morocco or Algeria to Spain. (There is also an Eastern Mediterranean Route, the Aegean crossing from Turkey to Greece, the preference of migrants from West Asia.) The three dozen research papers compiled in this substantial edited volume from the International Organization for Migration (IOM) offer a wealth of up‐to‐date information on migrants and migration along the West and North African paths converging on these routes, especially the CMR.

An equally or more important achievement of the editors is to place this Europe‐ward flow in context as a minor part of long‐established and now rising population mobility within the whole region. The “CMR countries” in Africa—from Nigeria to Tunisia and from Mauritania to Sudan or Eritrea—have a population comparable in size to Europe's. Their borders are porous. Labor migrants from Mali, Niger, Chad, and Burkina Faso are attracted to the cocoa, coffee, and groundnut plantations of Ghana, Senegal, and Côte d'Ivoire or to Nigeria's burgeoning industrial and service economy; others seek employment in oil‐rich Libya and Algeria. Country case studies in the volume describe many of these movements. Migrants interviewed in Libya mostly had jobs and were sending remittances home; they had no aspirations to reach Europe. Few attempted the hazardous sea crossing: as Philippe Fargues notes in the introduction, “it is by air and with a visa that the majority of African migrants to Europe reach their destination.”

The contents are arranged under the four broad topics signaled in the subtitle: key migration and mobility trends; risks and challenges faced en route; migrants' (generally positive) effects on economic development; and migration policies and governance. Several early chapters examine data collection issues in the face of the major deficiencies encountered. Estimates of migrant stocks are available from censuses and fragmentary administrative records, and lately from Facebook location data, but these sources say nothing about flows and routes, let alone migrants' experiences and intentions. Novel data collection methods devised by the IOM and the Mixed Migration Centre (an independent policy research organization institutionally linked to the Danish Refugee Council) are described that draw on recurrent interviews by field monitors with key informants, including smugglers, at migrant hubs and border‐crossing points, designed to generate longitudinal tracking data and migrant profiles. At some sacrifice in randomness, these methods yield both quantitative estimates and rich depictions of the migration experience. Their use is illustrated in later chapters.

The CMR picture familiar in the Western media is of privation and human trafficking across the Sahara, abuse and exploitation of migrants in post‐Gaddafi Libya, ending with the dangers of the sea voyage and uncertain reception in Europe. While this account is roughly confirmed, the volume offers a more complex and nuanced view. Gabriella Sanchez, for example, presents a case study of the dynamics of migrant smuggling in Libya. Most south‐to‐north migrants use the services of smugglers. Far from being organized criminal networks, the interview data show the smugglers to be from poor communities, generating modest incomes from their activities. “Transporting migrants across long distances or from remote locations for a fee was in this sample socially perceived as a legitimate form of labour without the stigma and risk present in other forms of smuggling, such as drugs or weapons.” But another chapter, by Luca Raineri, finds a contrasting situation for sea crossings, where strengthened barriers to entry into the human trafficking market encourages organized crime. “Trends recently detected in the region point to the progressive conversion of smuggling activities into thriving trafficking businesses, involving the exploitation of migrants and asylum seekers, and the trade of narcotic drugs.”

The main contents of the volume refer to the period 2018–2019. The contributions were largely completed before the worldwide spread of Covid‐19 in early 2020, with its potentially deep and ramifying effects on migration. An added introductory chapter by Irene Schöfberger and Marzia Rango considers these effects in the CMR region, to the extent they could be discerned up to July 2020. They include the much reduced numbers of arrivals in Europe; the stranding of many migrants by border closures; major falls in remittances; and disproportionately adverse health impacts on migrants.

The lead editors are Philippe Fargues and Marzia Rango. Fargues is at the European University Institute; Rango is with IOM´s Global Migration Data Analysis Centre, Berlin. Many of the chapter authors are based in IOM country offices in the region. Chapter bibliographies, annexes. The volume is free to download from the IOM website; hard copies are thus far not available.

前往欧洲的“非正规”非洲移民和寻求庇护者主要选择从利比亚到意大利或马耳他的所谓中地中海航线（CMR），或从摩洛哥或阿尔及利亚到西班牙的西地中海航线。（还有一条东地中海之路，从土耳其到希腊的爱琴海过境，是西亚移民的优先选择。）国际移民组织（IOM）在这本经大量编辑的研究中编写的三打研究论文提供了丰富的经验。关于沿这条路线汇聚的西非和北非路径上的移民和移民的最新信息。

编辑者的一项同等或更重要的成就是，将欧洲范围内的人口潮作为背景，作为整个地区长期存在且现在正在增加的人口流动的一小部分。从尼日利亚到突尼斯，从毛里塔尼亚到苏丹或厄立特里亚，非洲的“ CMR国家”的人口规模可与欧洲媲美。它们的边界是多孔的。来自马里，尼日尔，乍得和布基纳法索的劳务移民被加纳，塞内加尔和科特迪瓦的可可，咖啡和花生种植园吸引，或者被尼日利亚蓬勃发展的工业和服务经济所吸引；其他人则在石油资源丰富的利比亚和阿尔及利亚寻找工作。大量的国家案例研究描述了其中的许多运动。在利比亚接受采访的移民大多有工作，正在汇款回家。他们没有到达欧洲的愿望。

在副标题中指出的四个主要主题下安排内容：主要的迁移和流动趋势；途中面临的风险和挑战；移民对经济发展的影响（通常是积极的）；以及迁移政策和治理。面对早期的主要缺陷，前几章研究了数据收集问题。可以从人口普查和零散的行政记录中以及最近从Facebook的位置数据中获得对移民库存的估计，但是这些消息来源都没有提到流量和路线，更不用说移民的经历和意图了。本文描述了IOM和混合移民中心（与丹麦难民理事会建立机构关系的独立政策研究组织）设计的新颖数据收集方法，该方法利用了现场监测员在移民中心和边境地区对包括走私者在内的主要信息提供者的定期采访。交叉点，旨在生成纵向跟踪数据和移民档案。在牺牲一些随机性的情况下，这些方法既产生了定量估计，又给出了迁移经验的丰富描述。在后面的章节中将说明它们的用法。

西方媒体熟悉的CMR图片是撒哈拉以南地区的匮乏和人口贩运，卡扎菲后利比亚对移民的虐待和剥削，其结果是海上航行的危险和在欧洲的接收不确定。尽管此帐户已得到大致确认，但该卷提供了更为复杂和细致的视图。例如，加布里埃拉·桑切斯（Gabriella Sanchez）提出了一项关于利比亚移民走私动态的案例研究。大多数南北移民都使用走私者的服务。访谈数据显示，走私者并非来自犯罪社区，而是有组织的犯罪网络，他们的活动产生了可观的收入。“在这个样本中，将移民长途或从偏远地区转移到移民那里被视为社会上的合法劳动形式，而没有毒品或武器等其他形式的走私所带来的污名和风险。” 但是，卢卡·雷内里（Luca Raineri）撰写的另一章则发现了跨海地区的情况截然相反，在这种情况下，加强进入人口贩运市场的障碍会鼓励有组织犯罪。“最近在该地区发现的趋势表明，走私活动逐渐转变为蓬勃发展的贩运业务，涉及剥削移民和寻求庇护者以及麻醉药品贸易。” 加强进入人口贩运市场的壁垒会鼓励有组织犯罪。“最近在该地区发现的趋势表明，走私活动逐渐转变为蓬勃发展的贩运业务，涉及剥削移民和寻求庇护者以及麻醉药品贸易。” 加强进入人口贩运市场的壁垒会鼓励有组织犯罪。“最近在该地区发现的趋势表明，走私活动逐渐转变为蓬勃发展的贩运业务，涉及剥削移民和寻求庇护者以及麻醉药品贸易。”

该卷的主要内容是指2018-2019年期间。这些贡献在2020年初Covid‐19在全球范围内传播之前已基本完成，这可能会对迁移产生深远的影响。IreneSchöfberger和Marzia Rango在添加的介绍性章节中，考虑了到2020年7月对CMR地区产生的影响，这些影响可以被识别到欧洲。边境关闭使许多移民滞留；汇款大幅下降；以及对移民的不利健康影响。

主要编辑是Philippe Fargues和Marzia Rango。Fargues在欧洲大学学院任教；Rango在柏林IOM全球迁移数据分析中心工作。本章的许多作者都来自该地区IOM国家办事处。第一章参考书目，附件。该卷可从IOM网站免费下载；到目前为止，没有纸质版。