Political and economic policy, developments in the financial and commodity markets, and a nation’s current situation affect consumers. Consumer confidence is crucial for policymakers, the economic environment, and the public and private sectors. Recently, countries have begun surveying the consumer confidence of their citizens. In Turkey, consumer confidence, called Consumer Confidence Index (CCI), is determined by the monthly Consumer Tendency Survey by the Central Bank of Turkish Republic (CBRT) and the Turkish Statistical Institute (TURKSTAT). The survey reveals assessments from consumers regarding the current market situation and their financial situations and expectation of the forthcoming period. The CCI is valued from 0 to 200, following the results of the survey. If the value is greater than 100, it indicates optimistic consumer confidence. However, a value less than 100 indicates pessimistic consumer confidence. 

This study aims to identify the relationship between monthly fluctuations in the real profit gained by financial investment tools, adjusted by Consumer Price Index (CCI) and the monthly fluctuation in CCI. The real profit rates for financial investment tools, including deposit rates, BIST100 share index, gold (ingot), USD, Euro, and Government Domestic Debt Instruments (GDDI) are calculated monthly, quarterly, biannually, and annually by adjusting with CCI or Domestic Producer Price Index (PPI). 

The existing literature has not revealed any work related to this aim, and it is expected that this study will contribute to the literature. Data used in the analysis were imported from TURKSTAT’s database. The analysis period began on 2006:01 and ended on 2019:08asGDDI’s real profit was first released by TURKSTAT on 2006:01. 

The Granger Causality test was used to determine the relationship between variables as the test determines the direction of relations between variables while being stationary at the same order. Before the test, the stationarity with variables graphs was examined with Augmented Dickey–Fuller (ADF) and Phillips–Perron unit root tests. According to graphs, the variables fluctuate around zero mean, that is, it may be inferred that the variables are at level stationary, i.e., I (0). Consequently, because of the unit root tests, the variables have no unit root and indicate level stationarity properties. Therefore, the co-integration test was not implemented to determine the long-term relationship between variables.

As a result of the Granger causality test, while BIST100, Dollar, Euro, and gold’s real profit affect CCI, the relationship is not reciprocal and CCI does not affect these variables. On the other hand, the deposit rate and GDDI do not affect CCI. However, CCI solely affects GDDI. When BIST100, Dollar, Euro, and gold’s real profit go up, consumers’ investing decisions will increase. Consequently, consumer confidence will be optimistic, and vice versa. Conversely, fluctuations in deposit rates and GDDI’s real profit do not change consumer confidence. Nevertheless, CCI is a very important indicator for governments because monthly fluctuations of CCI change DIBBS’s real profit. Accordingly, when governments want to build debt, they could consider consumer confidence because if CCI increases, they may want to become indebted. In summation, one concerned with consumer confidence should pay special attention to CCI.