1. Lecture 9: Secondary Data
Research Methods I
Lecture 9: Secondary Data

2. 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

3. 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.

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

5. 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

6. 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

7. 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)

8. Electronic Data - Literature
You can search by author or subject across journals, via several static websites/portals:

9. 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

10. OECD: http://www.oecd.org/statsportal/0,2639,en_2825_293564_1_1_1_1_1,00.html
ONS:
UN:
Penn World Tables:
BEA (US):
Ameristat:

11. Eurostat: http://epp. eurostat. cec. eu. int/portal/page
World Bank:
CIA:
US Statistical Abstract:

12. 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