STS 242 - Socio-Economic Statistics

Operations and Publications of Official Statistical Organisations in Nigeria

• Official Statistics refers to the totality of statistics produced by public statistical agencies of a country, covering economic and social statistics.
• A national statistical system consists of people, procedures, data, and equipment for data processing and dissemination.
• There are two types of national statistical systems:
  • Centralised system: where the whole process of data production and dissemination is carried out by an organ of the government.
  • Decentralised system: where there is a division of responsibility between various data collection agencies at different tiers of government.

Nigeria National Statistical System

• The Nigerian National Statistical System is a decentralised system.
• The system consists of:
  • Producers of statistics: including the National Bureau of Statistics (NBS), federal ministries, public agencies, state statistical agencies, and local government statistics units.
  • Data users: including key users such as policy and decision makers.
  • Data suppliers: including establishments and households.
  • Research and training institutions: including higher education institutions.

Objectives of Nigeria National Statistical System

• To raise public awareness about the importance and role of statistical information to society.
• To collect, process, analyse, and disseminate quality statistical data.
• To promote the use of best practices and international standards in statistical production, management, and dissemination.
• To promote the use of statistical data and information at individual, institutional, local government, national, and international levels.

Coordination of Nigeria National Statistical System

• The system is coordinated by the governing board of the NBS.
• The board takes policy decisions and monitors the coordination of the system.
• The National Consultative Committee on Statistics is another mechanism for coordinating the system, headed by the Statistician General.

Functions of Coordinating Agencies

• To examine the statistical programmes of the various agencies annually.
• To develop strategies to ensure uniform standards and methodologies among agencies.
• To improve the quality, comparability, and timeliness of statistics output.

Nature of Socio-Economic Statistics

• Economic statistics are historical records of economic activity, guiding the understanding of an economic system and policy formulation.
• Social statistics refer to data generated on the condition and quality of life of people.

Major Producers of Socio-Economic Statistics in Nigeria

• National Bureau of Statistics (NBS): the main national agency responsible for the development and management of official statistics in the country.
• National Population Commission of Nigeria: responsible for the enumeration of the population, conducting research, and providing information on population for national planning and economic development.
• Central Bank of Nigeria: publishes banking, financial, agricultural, and foreign trade statistics.

Sources of Economic and Social Statistics

• Published national sources: including statistical abstracts, bulletins, and reports issued by government departments.
• Published international sources: including publications of international institutions such as the IBRD, IMF, and ECA.
• Administrative statistics: data collected from government and non-government agencies.

Uses of Economic and Social Statistics

• Planning for national development.
• Construction of systems of national accounts.
• Construction of economic models.
• Policy formulation and decision-making.

Problem of Collecting Economic and Social Statistics in Nigeria

• Conceptual problems: including shortage of well-qualified statistical manpower.
• Problems in the statistical system: including inadequate coordination, cooperation, and collaboration among major producers of statistics.
• Problems in society: including lack of statistical awareness, illiteracy, and cultural/religious problems.

Designs for Data Collection

• Primary data: collected at first hand for a specific purpose.
• Secondary data: data that already exists and may be adapted for use in the current survey.
• Methods of collecting quantitative primary data: including interview, experimental, and observation methods.
• Methods of collecting qualitative primary data: including in-depth interviews and focus group discussions.

Design of Questionnaires

• A questionnaire is a document or form that contains questions designed to collect statistical information.
• Objectives of questionnaire design: to collect required information, facilitate interviewing or responses, and facilitate data processing.
• Basic steps in questionnaire design: identify the type of data required, specify the type of information, write a first draft, revise, pre-test, and produce a final draft.

Index Numbers

• An index number is a statistical device used to measure changes in price, quantity, or value of a group of related items over a period of time.
• Index numbers are always expressed in terms of a base of 100.Here are the study notes for the text:

Construction of Price Indices

• A standard convention is used to denote prices, quantities, and values at different time points: Po, Qo, Vo for base time point, and Pn, Qn, Vn for another time point.
• Two rules should be observed when selecting a base period: (1) the period should be one of economic normalcy or stability, and (2) the base period should be recent to minimize the effect of changing technology, products, and quantities.

Index Relatives or Simple Index Number

• An index relative measures the change in a distinct commodity over time.
• The formula for calculating an index relative is Ip = Pn/Po x 100.

Time Series of Relatives

• There are two ways to calculate relatives in a time series: fixed-base relatives and chain-base relatives.
• Fixed-base relatives are calculated based on a fixed time point, while chain-base relatives are calculated based on the immediately preceding time point.

Composite Indices

• A composite index number is obtained by combining information from a set of economic commodities of like kind.
• There are two types of composite indices: weighted and unweighted indices.

Unweighted Indices

• A simple aggregate index (SAI) is calculated as SAI = ∑Pn/∑Po x 100.
• The mean of price relatives is calculated as Π = (∑(Pn/Po) x 100)/k, where k is the number of items.

Weighted Indices

• Weighted average of relatives is calculated as I = ∑WI/∑W.
• Weighted aggregate index is calculated as IAG = ∑WVn/∑WVo x 100.

Specific Types of Indices

• Laspeyres index: Lp = ∑qopn/∑qopo x 100.
• Paasche index: Pp = ∑qnpn/∑qnpo x 100.
• Fisher's ideal index: Fp = √Lp x Pp.
• Marshal-Edgeworth index: Mp = ∑Pn(qo + qn)/∑Po(qo + qn) x 100.

Uses of Index Numbers

• Index numbers are used to show relative changes in economic variables over time.
• They are used to reflect general economic conditions, such as the cost of living, standard of living, etc.
• They provide useful inputs for planning, budgeting, and making economic forecasts.

Limitations of Index Numbers

• They indicate general (aggregate) rather than specific changes.
• They may be misinterpreted, and sampling errors can occur.
• Weighting factors may become outdated.
• Organisations entrusted with publishing indices may not be reliable.

Time Series Analysis

• Time series data are collected at regular intervals over a period of time.
• The components of a time series include the secular trend, seasonal variation, cyclical variation, and irregular variation.

Components of Time Series

• Secular trend: a smooth, long-term movement of the series over time.
• Seasonal variation: a periodic movement that does not extend beyond a year.
• Cyclical variation: a recurrent up and down movement over a long period.
• Irregular variation: unpredictable variations caused by isolated special occurrences.

Models of a Time Series

• Additive model: Y = t + s + c + i.
• Multiplicative model: Y = tsci.

Estimation of Components

• Long-term trend can be estimated using the freehand method, method of semi-averages, method of moving averages, or the least squares method.

Least Squares Method

• The least squares trend equation is Vt = a + bt, where b = ∑Vt/∑t2, and a = ∑v/N.
• The trend values for each period are estimated using the trend equation.### Moving Averages and Seasonal Variation Indices

3-Year Moving Averages

• Calculate 3-year moving totals and moving averages to analyze business trends
• Example: Calculate 3-year moving averages for a business conglomerate's turnover from 1983 to 1996

Centred Moving Averages

• Calculate centred moving averages to correspond to the true median period
• Calculate centred moving averages by summing up values of two adjacent moving totals and dividing the resulting values by 2k (where k is the number of periods in each moving total)
• Example: Calculate centred moving averages for a company's quarterly turnover from 1994 to 1996

Seasonal Variation Indices

• Determine the seasonal component of a time series by removing the effects of trend, cyclical, and irregular components
• Seasonal variation indices can be determined using:
  • Average percentage method
  • Ratio-to-trend method
  • Ratio-to-moving-average method
  • Link relative method

Average Percentage Method

• Based on the assumption of an additive relationship between the components of a time series (V = T + S + C + I)
• Steps:
  1. Average the figures of each of the corresponding time points
  2. Fit a least square trend line to the averages obtained in step 1 to determine the incremental rate 'm'
  3. Obtain an estimate of the expected increase in the value of the series along the trend line
  4. Deduct the estimate of the incremental trend value of each seasonal period from the corresponding seasonal period average
  5. Obtain the seasonal indices by expressing each of the seasonal values as a percentage of their average

Ratio-to-Trend Method

• Assumes a multiplicative relationship between the components of the time series (V = T × S × C × I)
• Steps:
  1. Estimate a least square trend line of the series, and use the trend equation to estimate the trend values for each of the time points
  2. Obtain percentage of trend values
  3. Obtain the average for each of the different seasonal periods, using mean or median
  4. Obtain the seasonal indices