In this paper, we study newspaper partisan behavior and content, which we measure using coverage of and commentary on partisan activities, institutions, and actors. We use this measure to describe the levels of relative partisan behavior during the period 1880 to 1900, and to describe changes over the period 1880 to 1980. We find that, on average, newspapers were initially highly partisan, but gradually became less partisan over time. Importantly, we find as much change after the 1910s as before, which contributes to the existing literature that focuses on changes in the nineteenth and early twentieth centuries. We also investigate words and phrases that had negative or positive partisan connotations in particular periods. Finally, we examine whether some of the common hypotheses offered in the literature can account for the changes. The initial findings suggest that these explanations can only account for part of the decline.

在本文中，我们研究报纸的党派行为和内容，并通过对党派活动、机构和参与者的报道和评论来衡量。我们使用这一衡量标准来描述 1880 年至 1900 年期间的相对党派行为水平，并描述 1880 年至 1980 年期间的变化。我们发现，平均而言，报纸最初具有高度党派色彩，但随着时间的推移逐渐变得不那么党派色彩。重要的是，我们发现 1910 年代之后的变化与之前一样多，这有助于现有文献关注 19 世纪和 20 世纪初期的变化。我们还调查在特定时期具有消极或积极党派含义的单词和短语。最后，我们研究文献中提供的一些常见假设是否可以解释这些变化。初步调查结果表明，这些解释只能解释部分下降的原因。