Commodity Flow Survey (CFS) 2012 [Public Use Microdata File]

The Commodity Flow Survey (CFS) is a joint effort by the Bureau of Transportation Statistics (BTS) and the U.S. Census Bureau, U.S. Department of Commerce. The survey is the primary source of national and state-level data on domestic freight shipments by establishments in mining, manufacturing, wholesale, auxiliaries, and selected retail and services trade industries located in the 50 states and the District of Columbia. The survey produces estimates on the type, origin and destination, value, weight, modes of transportation, distance shipped, and ton-miles of commodities shipped. The CFS is conducted every five years as part of the Economic Census. It provides a modal picture of national freight flows, and represents the only publicly available source of commodity flow data for the highway mode. The CFS was conducted in 1993, 1997, 2002, 2007 and most recently in 2012. This document describes the Public Use Microdata (PUM) File created for the 2012 Commodity Flow Survey (CFS). This user guide provides a brief description of the CFS and the differences between the CFS data used to create the published estimates and the records available in the PUM file. This document also explains how to create estimates and measures of sampling variability from the PUM file data. For a complete description of the CFS and access to the published tables, visit the CFS website at: www.census.gov/econ/cfs/. This is an experimental data product and comments from users regarding the content and usefulness of this product are appreciated. Contact the CFS staff by e-mail ([e-mail]) or phone [phone]) with your comments.

商品流动调查（Commodity Flow Survey, CFS）由美国运输统计局（Bureau of Transportation Statistics, BTS）与美国商务部人口普查局（U.S. Census Bureau, U.S. Department of Commerce）联合发起。本调查是获取美国50个州及哥伦比亚特区内，采矿业、制造业、批发业、辅助服务业及选定零售与服务贸易行业经营主体的国内货运数据的国家级与州级核心数据源。该调查可生成货运商品的类型、起讫地点、价值、重量、运输方式、运输距离以及货运吨英里数的相关估算值。

CFS每五年开展一次，作为经济普查（Economic Census）的组成部分。它完整呈现了全国货运流动的运输方式分布全貌，同时也是唯一可公开获取的公路货运货流数据来源。CFS分别于1993年、1997年、2002年、2007年开展，最近一次调查于2012年进行。

本文件旨在介绍为2012年商品流动调查（CFS）编制的公共使用微数据（Public Use Microdata, PUM）文件。本用户指南简要概述了CFS，以及用于生成官方发布估算值的CFS数据与PUM文件中可用记录之间的差异。此外，本文件还说明了如何基于PUM文件数据估算抽样变异性指标并生成相关测度。如需了解CFS的完整说明并获取官方发布表格，请访问CFS官方网站：www.census.gov/econ/cfs/。

本产品为试验性数据产品，欢迎用户就本产品的内容与实用性提出宝贵意见。用户可通过电子邮件（[e-mail]）或电话[phone]）联系CFS项目团队反馈相关意见。