As central banks around the world embrace negative rates, fear among public is moving up regarding the issue. Last week, newspapers from Japan reported that people are looking to store or park money elsewhere. Some are looking to buy to gold to safe guard money, others are looking to buy their personal vaults.

Miniature vaults are in fashion these days, according to Japanese national newspaper Yomiuri Shimbun. Sales of miniature vaults for home use has gone up many a fold, since Bank of Japan (BOJ) introduced negative rates.

According to Shimbun report, "owners of small and medium enterprises as well as the elderly are buying the mini-vaults" to keep their money in boxes. Though, ordinary consumers are unlikely to be hit by negative rates, it seem the introduction had profound effect on psyche. Though not in negative deposit rates are miniscule. According to Nikkei, Japan's biggest banks have reduced deposit rates on savings account to 0.001% after BOJ decision.

Moreover retail traders and investors are losing their access to bonds and yields go negative. Last week, interbank rate has turned negative for first time.

Research by Oxford economics suggest the cost may not be very high for physically storing liquidity. It would take just about 16 cubic meter space to store ¥ 1 billion.

This retail level action shows, if negative rates drop to such level that physical storage cost less, central banks might saw the deposits drop and Banks choosing the physical vaults to store money.

So negative rates <= cost of physical storage+ insurance+ cost of transfer