The “secret savings” of Japanese housewives hit a three-year low in 2010 as they were forced to compensate for slumping family incomes with the hidden reserves, according to a survey.

The value of hesokuri – the cash and investments that housewives stash away without telling their husbands – came to an average 3.08 million yen (€27,000) last year, a unit of Sompo Japan Insurance Inc. found in a survey.

It was the lowest level since 2007, according to the survey carried out in mid-December, covering 500 housewives across the nation who were on average 39.7 years old.

Hesokuri is a common practice in Japan, where married women tend to stay at home to look after their families’ domestic needs and squirrel away a small portion of their husbands’ salaries as discretionary money.

But many of the respondents said they had to use more of the secret funds to pay daily bills last year, as family in-comes and bonuses decline at a time of economic fragility for Japan.

In 2010, 43 per cent of housewives said they were able to secure hesokuri, with the largest individual savings standing at 35 million yen compared with 100 million yen a year ago, the poll showed.