Decaiile

Decaiile is a term that appears primarily in Romanian statistical contexts. It refers to the plural form of “decai,” which denotes the decile categories used to divide a ranked dataset into ten equal portions. In practice, analysts may calculate decaiile of a national income distribution to illustrate how wealth is distributed across the population. For instance, the first decai (90‑percentile threshold) captures the lower ninety percent of earners, while the tenth decai identifies the top ten percent. By examining decaiile, policymakers can assess socioeconomic inequality, target welfare programs, and compare trends over time.

The concept of decaiile is part of a broader suite of statistical metrics—including percentiles, quartiles, and median—that are routinely reported by national statistics offices. In many countries the terminology is translated into the local language, so in Romania the word appears in official reports and academic papers. The process of computing decaiile follows standard ranking techniques: the data are sorted, the observations are split into ten groups of equal size, and the boundaries of each group are recorded.

Decaiile can also be found in descriptive statistics curricula, and in recent literature it is sometimes used as a pedagogical example for illustrating data scaling and distribution shape. Although not as widely recognized internationally as the English term “decile,” the concept is mathematically equivalent and serves the same analytical purposes.