For many years, debates over the effectiveness of the patent system have focused on the central issue of “patent quality.” The purported decrease in patent quality over the past decade or two supposedly led to diminished innovation due to increased licensing and litigation costs as well as to reduced sequential innovation in various industries. Of course, “patent quality” may have varying meanings, which depend on the user and the context. This paper presents the first large-scale analysis of patent application and granted patent scope changes by looking at changes to independent claims during examination at the Patent Office. Our results show that applications with narrower claims at publication are more likely to be granted than those with broader claims. Further, we find that applications with narrower claims at publication take less time to examine than those with shorter independent claims. We find that the examination process tends to narrow independent claims, and to reduce the number of independent claims between publication and grant.