Overview of the Chapter
This chapter, Collection of Data, introduces students to the fundamental concepts and methods involved in gathering data for economic analysis. It covers the importance of data, sources of data, and various techniques for data collection, ensuring students understand how reliable data forms the basis of economic research and policymaking.
Meaning of Data
Data refers to quantitative or qualitative information collected for analysis, interpretation, and decision-making in economics.
Data can be numerical (quantitative) or descriptive (qualitative) and is essential for understanding economic trends and behaviors.
Sources of Data
Data can be collected from two primary sources:
- Primary Data: Collected firsthand for a specific purpose through surveys, experiments, or observations.
- Secondary Data: Obtained from existing sources like government reports, journals, or previous research studies.
Methods of Collecting Primary Data
Primary data collection involves several techniques:
- Direct Personal Investigation: The researcher collects data directly from respondents.
- Indirect Oral Investigation: Information is gathered through interviews with third parties.
- Questionnaires and Schedules: Structured forms used to collect standardized responses.
- Telephonic Interviews: Conducting surveys over the phone for quick data collection.
Census vs. Sample Survey
Census: A complete enumeration of the entire population under study.
Sample Survey: Data collection from a representative subset of the population.
While a census provides comprehensive data, it is time-consuming and costly. A sample survey is more efficient but requires careful selection to avoid bias.
Sampling Methods
Different sampling techniques include:
- Random Sampling: Every individual has an equal chance of being selected.
- Stratified Sampling: Population divided into subgroups (strata) and samples taken from each.
- Systematic Sampling: Selecting every nth individual from a list.
- Convenience Sampling: Choosing samples based on ease of access.
Errors in Data Collection
Common errors include:
- Sampling Error: Occurs due to differences between sample and population.
- Non-Sampling Error: Arises from data recording mistakes, biased responses, or faulty instruments.
Importance of Reliable Data
Accurate data collection ensures valid economic analysis, policy formulation, and business decisions. Poor-quality data can lead to incorrect conclusions and ineffective policies.