Chapter 2, Secondary Consumer Data Video Solutions, Statistics for Marketing and Consumer Research

Problem 1

Suppose you need to estimate the average weekly petrol consumption of London citizens. Consider the following three options
a. A magazine called Londoners on the road publishes an article stating that they have interviewed 2,000 of their subscribed readers by telephone last Saturday and recorded an average expenditure on petrol of $£ 15$. Considering that the price of petrol is about $£ 0.90$ per liter, one can estimate that the weekly consumption of petrol is: $15 / 0.90 \cdot 7$ days $=116.67$ liters per citizen per week. The magazine providing secondary data costs you $£ 2$.
b. Using secondary data from three retail chains' petrol stations one can build a data-set recording liters purchased in 20 randomly chosen London outlets each day of the last month. This produces a daily average of 78.3 liters per day per drive. Obtaining the set of secondary data from the three retailers costs you $£ 1,000$.
c. You can select a random sample of 500 London citizens and record their petrol consumption every day over one month. You get a final estimate of 71.5 liters per day. Primary data collection costs you $£ 40,000$.
1 Which one is the most reliable measure? Why?
2 Without prior knowledge of the size of difference in the final estimate and considering the rules of box 2.1, which secondary or primary data source would you choose? Why?

Jerrah Biggerstaff

Numerade Educator

12:38

Problem 2

Retrieve the following data from the web-site indicated
a. www.statistics.gov.uk (Her Majesty Statistical Office, UK): Monthly consumer price index for tobacco from 1996 to 2007 (D7CB)
b. www.bls.gov (Bureau of Labor Statistics, US) Consumer units with reference person under age 25 by income before taxes: Average annual expenditures and characteristics, Consumer Expenditure Survey, 2004-2005
c. ec.europa.eu/eurostat (Eurostat, European Union) Overall structure of consumption expenditure by detailed COICOP level (per thousand), 1999: coicop cp0321 Shoes and other footwear - all countries

Md.Daniyal Arshad

Numerade Educator

Problem 3

Open the EFS data-set in SPSS
a. Write down all of the variables measuring income. Can you indicate why they differ?
b. By using the information available on www.data-archive.ac.uk (see e.g. User Guide Vol. 1 of EFS 2004-5), comment on the quality of the data (% of refusals, no contacts, etc.)

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