| 来源类型 | Discussion paper |
| 规范类型 | 论文 |
| 来源ID | DP3104 |
| DP3104 Understanding Trend and Cycle in Asset Values: Bulls, Bears and the Wealth Effect on Consumption | |
| Martin Lettau; Sydney Ludvigson | |
| 发表日期 | 2001-12-12 |
| 出版年 | 2001 |
| 语种 | 英语 |
| 摘要 | This Paper describes the database on US patents that we have developed over the past decade, with the goal of making it widely accessible for research. We present main trends in US patenting over the last 30 years, including a variety of original measures constructed with citation data, such as backward and forward citation lags, indices of ?originality? and ?generality?, self-citations, etc. Many of these measures exhibit interesting differences across the six main technological categories that we have developed (comprising Computers and Communications, Drugs and Medical, Electrical and Electronics, Chemical, Mechanical and Others), differences that call for further research. To stimulate such research, the entire database ? about 3 million patents and 16 million citations ? is now available on the NBER website. We discuss key issues that arise in the use of patent citations data, and suggest ways of addressing them. In particular, significant changes over time in the rate of patenting and in the number of citations made, as well as the inevitable truncation of the data, make it very hard to use the raw number of citations received by different patents directly in a meaningful way. To remedy this problem we suggest two alternative approaches: the fixed-effects approach involves scaling citations by the average citation count for a group of patents to which the patent of interest belongs; the quasi-structural approach attempts to distinguish the multiple effects on citation rates via econometric estimation. |
| 主题 | Industrial Organization |
| 关键词 | Patents Citations Data construction Truncation |
| URL | https://cepr.org/publications/dp3104 |
| 来源智库 | Centre for Economic Policy Research (United Kingdom) |
| 资源类型 | 智库出版物 |
| 条目标识符 | http://119.78.100.153/handle/2XGU8XDN/532131 |
| 推荐引用方式 GB/T 7714 | Martin Lettau,Sydney Ludvigson. DP3104 Understanding Trend and Cycle in Asset Values: Bulls, Bears and the Wealth Effect on Consumption. 2001. |
| 条目包含的文件 | 条目无相关文件。 | |||||
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