If you were judge how an economy is doing well or poorly, it is natural to look at the total income that everyone in the economy is learning. That is the task of gross domestic product (GDP). This paper reflects the GDP computed by the total expenditure on the economy’s output of goods and services. To understand how the economy is using its scare resources, economists are often interested in studying the composition of GDP among various types of spending. To do this, GDP is divided into four components: consumption (C), investment (I), government purchases (G), and net exports (NX). This paper is concerned to government purchases analysis and especially to the influence of public services, which haven’t market value (such as: elaborating of a law, session of a tribunal, sitting of a law court etc.) on the GDP.