Trend Analysis of Final Construction Prices: The Turkish Case

Abstract

The 2003 year is accepted as a milestone in the Turkish procurement system. About fifteen years ago, the Public Procurement Law, nr. 4734 enacted instead of the State Procurement Law, nr. 2886. Although the current law was enacted with high expectations, e.g. prevention of the waste of public resources, the number of benchmark field studies conducted under this amendment is limited. Construction works constitute majority of the Turkish public procurements in monetary terms. This study investigates the trend analysis of the construction prices of public projects. The sample consist a total of 461 public building projects. 272 of these projects were procured in accordance with the State Procurement Law, nr. 2886 and 189 were procured in accordance with the Public Procurement Law, nr. 4734. These projects were completed in three metropolitans of Turkey as; Adana, Ankara and Gaziantep. Data of; completion month-year, contract price and final price of all these projects were collected. Trend analysis of the construction prices of the projects were performed separately for both procurement laws using Mann-Kendall analysis and Spearman's rho analysis. Increasing trends have been observed for both contract prices and final prices of the building projects. It was found that the signs of the financial crisis lived in November 2000 and February 2001 in Turkey could be read much earlier in the Turkish construction sector investments.

Keywords

• Construction works,final price,Mann-Kendall,procurement,Spearman's rho,trend analysis

References

1. [1] Statistics and the Reports of the Turkish Public Procurement Authority; http://dosyalar.kik.gov.tr/genel/Raporlar/2017_kamu_al%C4%B1mlar%C4%B1_izleme_raporu_rev3.pdf
2. [2] Brockman, J.L. "Interpersonal conflict in construction: cost, cause, and consequence." Journal of Construction Engineering and Management 140 (2014): 04013050. https://doi.org/10.1061/(ASCE)CO.1943-7862.0000805
3. [3] Chen, Y.Q., Zhang, Y.B., and Zhang, S. J. "Impacts of different types of owner contractor conflict on cost performance in construction projects." Journal of Construction Engineering and Management 140 (2014): 4014017. https://doi.org/10.1061/(ASCE)CO.1943-7862.0000852
4. [4] Buchholtz, J.D. An Investigation in Construction Cost Estimation Using a Monte Carlo Simulation. M.Sc. Thesis, OH: Air Force Institute of Technology, 2016.
5. [5] Karabulut, M., and Cosun, F. "Precipitation trend analyses in Kahramanmaraş." Turkish Journal of Geographical Sciences 7 (2009): 65-83 (in Turkish).
6. [6] Çıtakoğlu, H., Geyikli, M.S., and Demir, V. "Trend analysis of Aegean regional summer appliance evaporation data." 5th International Participation Soil and Water Resources Congress, Kırklareli, Turkey: 487-495, 2017 (in Turkish with English abstract).
7. [7] Yerdelen, C. "Investigation of trend analysis and change point detection for annual mean streamflows of Susurluk basin." Dokuz Eylül University Journal of Science and Engineering 15 (2013): 77-87 (in Turkish with English abstract).
8. [8] Ocal M.E., Laptali Oral E., Erdis E., and Vural G. "Industry financial ratios-application of factor analysis in Turkish construction industry." Building and Environment 42 (2007): 385–392.

9. [9] Alashwal, A.M., and Chew, M.Y. "Simulation techniques for cost management and performance in construction projects in Malaysia." Built Environment Project and Asset Management 7 (2017): 534-545, https://doi.org/10.1108/BEPAM-11-2016-0058
10. [10] Chege, P.W. Factors Affecting Housing Supply in Nairobi County, Kenya. M.Sc. Thesis, Nairobi: KCA University, 2017.
11. [11] Suveka, V., and Shanmuga Priya, T. "Prediction of material price using prediction tools- a comparision." International Journal of Scientific & Engineering Research 8 (2017): 160-164.
12. [12] Akgüç, Ö. Mali Tablolar Analizi. İstanbul: Muhasebe Enstitüsü, Publication nr: 64, 1995 (in Turkish).
13. [13] Bayram S. "Trend analysis of project durations of the school construction works." 2nd International Mediterranean Science and Engineering Congress, Adana, Turkey: 1393-1398, 2017 (in Turkish with English abstract).
14. [14] Helsel D.R., and Hirsch R.M. Statistical Methods in Water Resources. Studies in Environmental Science 49”, New York: Elsevier, 1992.
15. [15] Mann H.B. "Nonparametric tests against trend" Econometrica 13 (1945): 245–59.
16. [16] Kendall, M.G. Rank Correlation Methods. NY: Oxford University Press, 1975.
17. [17] Molinos-Senante, M., and Guzmán, C. "Benchmarking energy efficiency in drinking water treatment plants: Quantification of potential savings." Journal of Cleaner Production 176 (2018): 417-425.
18. [18] Pettitt, A.N. "A non-parametric approach to the change-point detection." Applied Statistics 28 (1979): 126-135.
19. [19] Hawkins, M. "Testing a sequence of observations for a shift in location." Journal of the American Statistical Association 72 (1977): 180-186.
20. [20] Wijngaard, J.B., Klein Tank, A.M.G., and Können G.P. "Homogenity of 20th century European daily temperature and precipitation series." International Journal of Climatology 23 (2003): 679-692.
21. [21] Ruxton G.D., and Neuhauser, M. "When should we use one-tailed hypothesis testing?" Methods in Ecology and Evolution 1 (2010): 114-117.