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In linear regression analysis, detecting anomalous observations is an important step for model building process. Various influential measures based on different motivational arguments and designed to measure the influence of observations on different aspects of various regression results are elucidated and critiqued. The presence of influential observations in the data is complicated by the presence of multicollinearity. In this paper, when Liu estimator is used to mitigate the effects of multicollinearity the influence of some observations can be drastically modified. Approximate deletion formulas for the detection of influential points are proposed for Liu estimator. Two real macroeconomic data sets are used to illustrate the methodologies proposed in this paper.

Identifying influential observations is an important step in the right direction of the linear regression model building process. Various influence measures based on different motivational arguments are designed to measure the influence of observations through different aspects of various regression models. This paper is on the result of the research studies on the local influence of minor perturbation on the Liu estimator in linear regression model. The diagnostics under the perturbations of constant variance, individual explanatory variables and assessing the influence on the selection of Liu estimator biasing parameter are derived for Liu estimator. Two real data sets are employed to illustrate our methodologies.Chinese Scholarship Council (CSC) Government of P.R. of Chin

In this paper, we use generalized influence function and generalized Cook distance to measure the local influence of minor perturbation on the modified ridge regression estimator in ridge type linear regression model. The diagnostics under the perturbation of constant variance and individual explanatory variables are obtained when multicollinearity presents among the regressors. Also we proposed a statistic that reveals the influential cases for Mallow's method which is used to choose modified ridge regression estimator biasing parameter. Two real data sets are used to illustrate our methodologies.

Introduction One of the important contributors to economic growth is Gross domestic product (GDP). The GDP is a monetary measure of the market value of all final goods and services produced in a specific period of time. Contemporary, the Sri Lankan economy has revealed a robust raising trend with per capita GDP reaching almost $4,000. Sri Lankan government has been implementing privatization and an open economy for worldwide competition which inspiring overseas investments from 1977. Resulting to the controlling of the leftist Janatha Vimukhti Peramuna (JVP), reforms and privatization attained a major enhancement and strain on growth due to export additionally aided in refreshing the performance of economy accelerating GDP growth attains to 7% in 1993. Some of the major international companies have realised the growth potential of Sri Lanka and made huge investments. In the subsequent years the Sri Lankan economy observed many disturbances resulting in irregular growth of economy but the overall mean yearly GDP growth was at 5.2% in 1999-2000.However, after independence, the first reduction in GDP was negative 1.4 in 2001.A sequence of universal and national economic complications such as terrorist assaults within Sri Lanka and international influences smashed the economy. The end of year 2001, the political managements was reformed by the parliamentary elections, that the Freedom Party of Sri Lanka retained the Premiership. After the alteration in administration the country acquired a progressive improvement in the economy. The economy profited from lower interest rates from 2002 to 2004,retrieval in domestic demand, improved tourist arrivals, a restoration of the stock exchange, and amplified foreign direct investment. Economic growth reached 4% in 2002, aided by strong sector growth. The recommencement of the civil war in 2005 directed to a sudden increase in security expenses. However, the economy began to grow in the year 2010 at an advanced rate of 8.0% as per the civil war finished in May 2009 and attained 9.1% in 2012, but again in 2013 fell to 3.4% and only marginally improved to 4.5% in 2014.These fluctuations of GDP growth rate were mainly caused due to the direct effects of consumer price index, gross domestic saving, money supply, government expenditure, exchange rate, exports prices of imports, interest rate, tax revenue etc. on gross domestic product due to the unstable circumstances of the country.