News coverage profoundly affects how countries and individuals behave in international relations. Yet, we have little empirical evidence of how news coverage varies across countries. To enable studies of global news coverage, we develop an efficient computational methodology that comprises three components: (i) a transformer model to estimate multilingual news similarity; (ii) a global event identification system that clusters news based on a similarity network of news articles; and (iii) measures of news synchrony across countries and news diversity within a country, based on country-specific distributions of news coverage of the global events. Each component achieves state-of-the art performance, scaling seamlessly to massive datasets of millions of news articles. We apply the methodology to 60 million news articles published globally between January 1 and June 30, 2020, across 124 countries and 10 languages, detecting 4357 news events. We identify the factors explaining diversity and synchrony of news coverage across countries. Our study reveals that news media tend to cover a more diverse set of events in countries with larger Internet penetration, more official languages, larger religious diversity, higher economic inequality, and larger populations. Coverage of news events is more synchronized between countries that not only actively participate in commercial and political relations -- such as, pairs of countries with high bilateral trade volume, and countries that belong to the NATO military alliance or BRICS group of major emerging economies -- but also countries that share certain traits: an official language, high GDP, and high democracy indices.

翻译：新闻覆盖深刻影响着国家及个人在国际关系中的行为模式。然而，关于不同国家间新闻覆盖差异的实证证据仍然匮乏。为推进全球新闻覆盖研究，我们开发了一套高效的计算方法，包含三个组成部分：（i）用于估算多语言新闻相似度的Transformer模型；（ii）基于新闻文章相似性网络进行事件识别的全球事件检测系统；（iii）基于各国对全球事件新闻覆盖的分布特征，衡量国家间新闻同步性与国内新闻多样性的量化指标。各组件均达到当前最优性能，并可无缝扩展至数百万篇新闻文章规模的超大数据集。我们将该方法应用于2020年1月1日至6月30日期间全球124个国家、10种语言发布的6000万篇新闻文章，检测出4357个新闻事件。我们识别出解释各国新闻覆盖多样性与同步性的关键因素。研究表明，互联网普及率更高、官方语言种类更多、宗教多样性更大、经济不平等程度更高、人口规模更大的国家，其新闻媒体倾向于覆盖更广泛的事件类型。新闻事件覆盖的同步性不仅存在于积极参与商业和政治关系的国家之间——例如双边贸易额较高的国家组合，以及属于北约军事联盟或金砖国家新兴经济体集团的国家——还存在于具有共同特征的国家之间：如共同官方语言、高GDP及高民主指数。