Research Methods I

Lecture 9: Secondary Data

Introduction

• In lectures 6 and 7, we considered primary and qualitative data • Primary data has several advantages, particularly control; qualitative data too • Do not equate primary and qualitative • Today: advantages of secondary data • Searching on electronic data sources including the Internet

Secondary data

• Primary/secondary is not = qualitative/quantitative • Qualitative can include secondary data sources such as personal documents, auto/biographies, etc.

• Secondary: collected by someone else, e.g. another academic researcher, business, government agency, etc.

Secondary data

• Used extensively in social science • Durkheim: suicide • Marx: wages, incomes, prices • Weber: church records • Economists mainly use secondary data

Advantages of Secondary Data

• Might be the only data available • Enables longitudinal /time series work • Cheaper (cost and time) and more convenient than primary data • Aids generalisation • Arises from natural settings (

nonreactive

/

unobtrusive

data) • Allows replication and checking - validity

Disadvantages of Secondary Data

• May be not exactly the data required • Differences in underlying sampling, design, questions asked, method of ascertaining information, etc.

• Differences lead to bias • Method of data generation crucial to econometric studies

Electronic Data Sources

• Through the library system • Through the internet • Known versus unknown sources • Known sources via library catalogue • Problem of reliability/credibility is common to all electronic sources (more than non-electronic sources)

Electronic Data - Literature

• • • • • You can search by author or subject across journals, via several static websites/portals: www.econlit.org/ www.sosig.ac.uk

www.mimas.ac.uk

www.economics.ltsn.ac.uk

Electronic Data: Databases

• There are many databases available online • Most have standardised, national data free to download in various formats • Common file format is .csv; but .html and even .xls files also common • For SPSS, save as .xls and SPSS will read automatically

• OECD: http://www.oecd.org/statsportal/0,2639,e n_2825_293564_1_1_1_1_1,00.html

• ONS: http://www.statistics.gov.uk

• UN: http://unstats.un.org/unsd/default.htm

• Penn World Tables: http://pwt.econ.upenn.edu

• BEA (US): http://bea.gov

• Ameristat: http://www.prb.org

• Eurostat: http://epp.eurostat.cec.eu.int/portal/page?=pageid=10 90,1137397&_dad=portal&_schema=PORTAL • World Bank: http://www.worldbank.org/data/onlinedat abases/onlinedatabases.html

• CIA: http://www.cia.gov/cia/publications.factb

ook • US Statistical Abstract: http://www.census.gov/statab/www/rank s.html

Conclusions

• Secondary data has many advantages and disadvantages relative to primary • There is a wide range of secondary data available • Much data is available on the internet • Internet sources must be scrutinised more closely than other sources