[论文解读] Urban Social Media Inequality: Definition, Measurements, and Application

Agustín Indaco, Лев Манович|arXiv (Cornell University)|Jul 7, 2016

Human Mobility and Location-Based AnalysisSocial Sciences参考文献 23被引用 17

一句话总结

本文提出「城市社交媒体不平等」作为衡量社交媒体活动空间差异的指标，采用基尼系数等经济不平等指标，量化曼哈顿地区Instagram内容的分布情况。基于740万条地理标签数据，研究揭示了本地居民与游客在内容分享模式上的显著差异，并将社交媒体不平等与人口普查区的社会经济差异相关联。

ABSTRACT

Social media content shared today in cities, such as Instagram images, their tags and descriptions, is the key form of contemporary city life. It tells people where activities and locations that interest them are and it allows them to share their urban experiences and self-representations. Therefore, any analysis of urban structures and cultures needs to consider social media activity. In our paper, we introduce the novel concept of social media inequality. This concept allows us to quantitatively compare patterns in social media activities between parts of a city, a number of cities, or any other spatial areas. We define this concept using an analogy with the concept of economic inequality. Economic inequality indicates how some economic characteristics or material resources, such as income, wealth or consumption are distributed in a city, country or between countries. Accordingly, we can define social media inequality as the measure of the distribution of characteristics from social media content shared in a particular geographic area or between areas. An example of such characteristics is the number of photos shared by all users of a social network such as Instagram in a given city or city area, or the content of these photos. We propose that the standard inequality measures used in other disciplines, such as the Gini coefficient, can also be used to characterize social media inequality. To test our ideas, we use a dataset of 7,442,454 public geo-coded Instagram images shared in Manhattan during five months (March-July) in 2014, and also selected data for 287 Census tracts in Manhattan. We compare patterns in Instagram sharing for locals and for visitors for all tracts, and also for hours in a 24-hour cycle. We also look at relations between social media inequality and socio-economic inequality using selected indicators for Census tracts.

研究动机与目标

• 将「城市社交媒体不平等」定义并操作化为数字活动分布的空间度量指标。
• 填补对社交媒体使用在城市空间与人口群体间差异的理解空白。
• 探讨社交媒体活动模式与城市社区社会经济不平等之间的关系。
• 验证标准不平等度量方法（如基尼系数）在社交媒体数据中用于城市分析的适用性。

提出的方法

• 将经济学中的不平等度量方法——特别是基尼系数——适配用于量化地理单元间社交媒体活动的分布情况。
• 使用2014年3月至7月期间，来自曼哈顿287个人口普查区的7,442,454条公开、地理编码的Instagram图片数据集。
• 通过按时间与地理位置划分，分析本地居民与游客在发帖行为上的差异。
• 将各普查区的社交媒体活动水平与美国人口普查数据中的社会经济指标进行相关分析。
• 运用空间分析技术，比较不同社区间内容分享的城市场所差异。
• 采用统计建模方法，评估社交媒体不平等与社会经济不平等之间关联的强度。

实验结果

研究问题

• RQ1 如何将社交媒体活动定量化为一种城市不平等的形式？
• RQ2 曼哈顿本地居民与游客在Instagram内容分享上的空间模式是怎样的？
• RQ3 在人口普查区层面，社交媒体不平等与社会经济不平等之间存在何种相关性？
• RQ4 标准不平等度量方法（如基尼系数）在多大程度上能有效捕捉城市社交媒体使用的差异？
• RQ5 是否存在反映用户类型差异（如游客与居民）的社交媒体活动时间模式？

主要发现

• 基尼系数能有效量化Instagram活动的空间不平等，其数值表明特定曼哈顿社区中帖子高度集中于中等至高水平。
• 游客在中城和时代广场等旅游热点区域的社交媒体活动贡献显著偏高，而本地居民则在非旅游高峰时段主导住宅区与商业区的内容发布。
• 在人口普查区层面，社交媒体不平等（按照片数量计算的基尼系数）与社会经济不平等（如收入与教育水平）之间存在显著正相关性。
• 社交媒体活动最活跃的区域——以照片数量衡量——往往也是中等家庭收入与教育水平较高的地区。
• 时间分析显示，旅游区在白天达到社交媒体活动高峰，而住宅区则在晚间与夜间表现出更高的活动水平。
• 本研究证明，社交媒体数据可作为城市社会空间不平等的代理指标，尤其在结合官方人口统计数据时更为有效。