ilker yoldas - Academia.edu (original) (raw)

Papers by ilker yoldas

This is a time-series analysis aimed primarily to test different macroeconomic models of consumpt... more This is a time-series analysis aimed primarily to test different macroeconomic models of consumption, or more specifically to test the consumers’ non-durable expenditure in the United Kingdom. It aims to examine the extent to which household consumption (the exogenous variable) is directly related to present income (the endogenous variable) but also to investigate the influence of past income levels.

The study involves Ordinary Least Squares (OLS) regression of aggregate United Kingdom consumption data to econometric functions, although focus is on the Keynesian and DHSY models. The period that is covered in this dissertation is between 1936, when Keynes introduced marginal propensity to consume, and 2004. Therefore, the literature review includes a mixture of both classical and recent works.

There are many potential issues in modelling the aggregate UK consumptions using time-series data. One example is the existence of uncontrolled - i.e. beyond the scope of what the model can capture based on theory - economic factors that affect annual consumption of non-durable goods leading to autocorrelation, heteroskedasticity, model misspecification and so forth. Thus, the economic reason for pursuing this study is to investigate how the components of the model relate to each other and to analyse the causes of the consequently biased models.

How can we explain our consumption of cocoa? Is it the caffeine in this hot, stimulating drink th... more How can we explain our consumption of cocoa? Is it the caffeine in this hot, stimulating drink that keeps us buying? But then again wouldn’t we substitute it for other hot, stimulating caffeine containing drinks like tea or coffee? Could sugar be a complementary product for cocoa? These are some of the interesting questions that are investigated and are attempted to be answered in this economic report.

The accuracy of the constant pi, which is the ratio of the perimeter over the diameter, developed... more The accuracy of the constant pi, which is the ratio of the perimeter over the diameter, developed in different cultures over time. This constant was investigated in these cultures from 1650 BC to 2000 AD and the early estimations of pi were merely based on its measurement. Mathematical approaches to estimate the value of pi came much later with Egyptians, Europeans, Greeks, Chinese, and Arabs.

One of the first mathematicians to provide a scientific method for calculating pi to a certain degree of accuracy was Archimedes of Syracuse. He estimated the value of pi using the areas and the semi-perimeters of two inscribed and the circumscribed regular polygons.

The most progress was made fastest in cultures that used the decimal system and in cultures that used the hexadecimal systems such as the Chinese and the Arabs. Not much progress was made in Europe where the Roman numerals were used which delayed the development.

In 1665 Isaac Newton from England estimated a value for pi by finding the area under the curve of a semicircle using integral calculus and a broader binomial theorem that he developed during the Great Plague Years.

A French mathematician George Louis Leclerc used probability to approximate the value of pi by randomly throwing a needle several times on a flat surface with parallel lines drawn on the surface and counting the number of times that the needle cut the lines.

A Swiss mathematician Johann Heinrich Lambert established the irrationality of in 1767, which indicated that the decimals of pi are not periodic. However, the irrationality of pi can also be demonstrated using statistics and goodness-to-fit test.

Unnecessary digits of pi were calculated in order to hold the record for the most accurate pi value. With the arrival of computers the accuracy of pi in technologically advanced cultures was boosted to thousands of digits and became a way to test technological capabilities of computers.

Consequently, cultures with advance mathematical tools have developed the most in calculating the value of pi.

After the discovery of the structure of Salicylic acid different companies started to produce Asp... more After the discovery of the structure of Salicylic acid different companies started to produce Aspirin in laboratories and made them commercially available. However, the chemical component of the tablet was not limited to the acid, which is the active substance, but also other chemical additives. These factors and some other properties change the effectiveness of the tablet.

Teaching Documents by ilker yoldas

This is a time-series analysis aimed primarily to test different macroeconomic models of consumpt... more This is a time-series analysis aimed primarily to test different macroeconomic models of consumption, or more specifically to test the consumers’ non-durable expenditure in the United Kingdom. It aims to examine the extent to which household consumption (the exogenous variable) is directly related to present income (the endogenous variable) but also to investigate the influence of past income levels.

The study involves Ordinary Least Squares (OLS) regression of aggregate United Kingdom consumption data to econometric functions, although focus is on the Keynesian and DHSY models. The period that is covered in this dissertation is between 1936, when Keynes introduced marginal propensity to consume, and 2004. Therefore, the literature review includes a mixture of both classical and recent works.

There are many potential issues in modelling the aggregate UK consumptions using time-series data. One example is the existence of uncontrolled - i.e. beyond the scope of what the model can capture based on theory - economic factors that affect annual consumption of non-durable goods leading to autocorrelation, heteroskedasticity, model misspecification and so forth. Thus, the economic reason for pursuing this study is to investigate how the components of the model relate to each other and to analyse the causes of the consequently biased models.

How can we explain our consumption of cocoa? Is it the caffeine in this hot, stimulating drink th... more How can we explain our consumption of cocoa? Is it the caffeine in this hot, stimulating drink that keeps us buying? But then again wouldn’t we substitute it for other hot, stimulating caffeine containing drinks like tea or coffee? Could sugar be a complementary product for cocoa? These are some of the interesting questions that are investigated and are attempted to be answered in this economic report.

The accuracy of the constant pi, which is the ratio of the perimeter over the diameter, developed... more The accuracy of the constant pi, which is the ratio of the perimeter over the diameter, developed in different cultures over time. This constant was investigated in these cultures from 1650 BC to 2000 AD and the early estimations of pi were merely based on its measurement. Mathematical approaches to estimate the value of pi came much later with Egyptians, Europeans, Greeks, Chinese, and Arabs.

One of the first mathematicians to provide a scientific method for calculating pi to a certain degree of accuracy was Archimedes of Syracuse. He estimated the value of pi using the areas and the semi-perimeters of two inscribed and the circumscribed regular polygons.

The most progress was made fastest in cultures that used the decimal system and in cultures that used the hexadecimal systems such as the Chinese and the Arabs. Not much progress was made in Europe where the Roman numerals were used which delayed the development.

In 1665 Isaac Newton from England estimated a value for pi by finding the area under the curve of a semicircle using integral calculus and a broader binomial theorem that he developed during the Great Plague Years.

A French mathematician George Louis Leclerc used probability to approximate the value of pi by randomly throwing a needle several times on a flat surface with parallel lines drawn on the surface and counting the number of times that the needle cut the lines.

A Swiss mathematician Johann Heinrich Lambert established the irrationality of in 1767, which indicated that the decimals of pi are not periodic. However, the irrationality of pi can also be demonstrated using statistics and goodness-to-fit test.

Unnecessary digits of pi were calculated in order to hold the record for the most accurate pi value. With the arrival of computers the accuracy of pi in technologically advanced cultures was boosted to thousands of digits and became a way to test technological capabilities of computers.

Consequently, cultures with advance mathematical tools have developed the most in calculating the value of pi.

After the discovery of the structure of Salicylic acid different companies started to produce Asp... more After the discovery of the structure of Salicylic acid different companies started to produce Aspirin in laboratories and made them commercially available. However, the chemical component of the tablet was not limited to the acid, which is the active substance, but also other chemical additives. These factors and some other properties change the effectiveness of the tablet.