CandleFocus

Survivorship Bias

Survivorship bias is a common logical error that results in selectively evaluating data points that have “survived” some type of selection process, while ignoring data points that “failed” and were discarded, thus exaggerating the importance of the data points that remain. Survivorship bias can lead to wrong conclusions about the data, and it mostly arises when the sample size is too small to make solid inferences or, more simply, when relevant information is ignored.

Survivorship bias affects many parts of our life and is a common in business decision-making, investment advice, and research studies. It can also occur in performance evaluations of active funds, ratings of hospitals and universities, or running memoirs/biographies of successful people.

Survivorship bias is often seen in the banking and finance industry, where mutual fund companies compare the performance of only active funds, without considering past funds that have been liquidated, closed, or merged. This may lead to wrong conclusions, as it fails to recognize the performance of the failed investments and only reflects those that have been most successful, thus overestimating overall performance.

Companies that use historical database analysis can also fall prey to survivorship bias. By only considering successful products, services, decision-making processes and other areas, companies can miss potential insights and solutions to current problems. This distortion of reality occurs when failing projects and data points are removed from a data set.

Investment advisers and investors should be aware of survivorship bias when interpreting returns and measuring investment performance. While it is important to consider past winners, it is equally important to look at prior losers or those investments that did not make it. By doing so, investors can compare multiple funds across a wide range of performance criteria.

Overall, survivorship bias has been recognized as having serious implications in data analysis and interpretation. As such, it should be avoided in order to make correct conclusions from historical data. In order to do so, investors and analysts should be sure to consider all relevant data when making assessments and to agree upon any arbitrary deletions of data before collecting results. Understanding the problem of survivorship bias will allow for more accurate evaluation of data sets and lead to better decision-making.

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