The labor ministry released on Wednesday corrected personal income statistics going back to 2012, after the discovery of sampling irregularities stretching back nearly 15 years that had resulted in benefits and compensation to some 20 million people going underpaid.
After correcting the labor survey data for the years still held by the Ministry of Health, Labor and Welfare, monthly average cash earnings per person were raised by up to 1.2 percentage points.
The ministry said records from 2004 to 2011 had been discarded because it was not required to keep them, but its own committee charged with probing the issue said that these should have been retained under laws relating to statistics and public record management.
The unprecedentedly extensive data correction comes after the committee concluded Tuesday that a statistics section at the ministry had approved a manual allowing the use of irregular sampling methods for the monthly labor survey. The survey is a key indicator of the country’s employment and wage conditions. Dozens of officials, including some who had already retired, have been reprimanded.
The ministry is required to survey all businesses in Japan with at least 500 employees but collected data from only a third of some 1,400 such companies in Tokyo since 2004, breaching the Statistics Act.
All monthly earnings since 2012 were corrected upward by at least 0.2 percentage point. The largest correction was for June 2016, with average income amended to ¥436,518 ($3,980) from ¥431,262.
The misconduct resulted in the underpayment of more than ¥50 billion in benefits to around 20.15 million people who were entitled to payments from unemployment insurance, workers’ compensation and sailors’ insurance.
The government was forced to rework the state budget for fiscal 2019 from April to address the problem.
The manual that documented the survey methods was updated every few years, and included phrases such as “accuracy (of data) can be ensured without surveying all businesses,” the ministry has said. Labor minister Takumi Nemoto has said that the phrases were removed in 2015.
Nemoto and his two deputies will return pay dating back to their appointment in October, while the ministry’s top bureaucrat, Toshihiko Suzuki, has been given a formal reprimand for failing to prevent the scandal.
The investigative committee found no definitive proof of a ministry-wide cover-up.