The time and frequency of unrelated diversification

•We study the frequency and timing of unrelated diversification using two international trade datasets.•We introduce a method to identify periods when countries enter unrelated products.•Unrelated diversification events are more common for countries at relatively high levels of complexity.•At low levels of complexity, locations are related to low complexity activities.•At high levels of complexity, this relationship reverses, and relatedness is no longer correlated with low complexity activities.