Research Article
Small Area Estimation of Household Consumption-expenditure Pattern in Nigeria During COVID-19 Pandemic
Udofia Blessing-Oxford Udeme,
Iseh Matthew Joshua*
,
Bassey Mbuotidem Okon
Issue:
Volume 13, Issue 4, August 2025
Pages:
63-75
Received:
14 June 2025
Accepted:
30 June 2025
Published:
23 July 2025
Abstract: The problem of Small Area Estimation is the non-availability of sample data in areas of interest. The idea behind this study is to adopt and modify some calibration estimators that could produce reliable estimates with minimum mean square error in small areas to determine the pattern of household consumption-expenditure in Nigeria before, during and after COVID-19 pandemic. A combined direct and synthetic ratio/regression estimators are used in the formulation of the longitudinal estimators. The bias and mean square errors of the estimators are derived using Taylor's series approximation techniques different from the existing estimators. It is observed that the calibrated estimators have provided more reliable estimates against the instability of the existing synthetic estimators and the higher variance of the existing direct estimators. Consequently, the gains made on the performance of the modified estimators cannot be overemphasized. From the empirical results, the performance of the suggested estimators are outstanding using the average mean square error, average relative bias and average coefficient of variation across the survey periods (WAVEs) of 2019, 2020 and 2021. This indicates that the use of auxiliary variable (income) into the existing estimators by calibration technique has yielded the desirable result which agrees with the literature. Again, this result is validated since the modified calibrated estimators provide estimates within the acceptable region of 25% benchmark of the average coefficient of variation in the area of interest. In addition, the performance of the estimators in predicting the estimates of the population mean expenditure are also carried out. The pattern of household consumption-expenditure signifies that households in Nigeria consumed more during COVID-19 period while at home and the consumption burden lessens after the pandemic. This study has established the use of auxiliary variable that is strongly correlated with the study variable in domain estimation where there is small/no sample data in areas of interest.
Abstract: The problem of Small Area Estimation is the non-availability of sample data in areas of interest. The idea behind this study is to adopt and modify some calibration estimators that could produce reliable estimates with minimum mean square error in small areas to determine the pattern of household consumption-expenditure in Nigeria before, during an...
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Research Article
Fermi Statistics Method Applied to Model Macroscopic Demographic Data
Giuseppe Alberti*
Issue:
Volume 13, Issue 4, August 2025
Pages:
76-91
Received:
25 October 2025
Accepted:
12 November 2025
Published:
11 December 2025
DOI:
10.11648/j.sjams.20251304.12
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Abstract: The study begins by considering an abstract object (cellular automaton) able of moving -by arbitrary decision- between two given fixed positions. That is, at each clock step, it can change position or remain stationary in its current position. This object, which we call an Arbitrary Oscillator (ArbO), cannot evolve indefinitely since it may encounter ‘end-of-life’ events, which are also random. If we place quantitative limits on the number of arbitrary events and impose that the life cycle of ArbO must end in any case, we can use Fermi statistics to find the most probable distribution of fatal events along the possible sequences of choices. This distribution is represented by a recursive function that can be calculated for each total number of possible ‘life/death’ choices, which we will call Total Cases (TC). By means of a time-scale adjustment, we have associated the distribution curves of ArbO ‘fatal’ events with the demographic mortality curves (dx and qx data) of populations in the case of Italy. To better study the properties of the statistical function thus found, we attempted a continuous transposition of the recursive equation, seeking solutions to the differential equation linkable with it. With a continuous analytical expression, the characteristics of this statistical distribution can be studied more effectively. Similarities and differences with demographic mortality curves have been highlighted, attempting to explain the latter as overlaps of curves with different TC parameters. Implications with life span and more general life cycle concepts are outlined. A correlation with a more recent study using a multi-omics approach is also pointed out.
Abstract: The study begins by considering an abstract object (cellular automaton) able of moving -by arbitrary decision- between two given fixed positions. That is, at each clock step, it can change position or remain stationary in its current position. This object, which we call an Arbitrary Oscillator (ArbO), cannot evolve indefinitely since it may encount...
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