Aftermath of the 2011 Tōhoku earthquake and tsunami highest in the world). This additional spending could hurt demand for government bonds. Silicon wafer production has been suspended at factories owned by Shin-Etsu Chemical and MEMC Electronic Materials, which together account for 25% of the global silicon wafer production. The suspension is expected to drastically impact semiconductor production, which is contingent on wafer availability. Some economic analysts consider that, ultimately, the catastrophe will improve Japan's economy, with increased job availability during restoration efforts. An analyst at JPMorgan Chase, citing the 1989 Loma Prieta earthquake in the San Francisco Bay Area and the Southern California 1994 Northridge earthquake, noted that
Earthquake prediction of having observed such phenomena prior to an earthquake, no such phenomena has been shown to be an actual precursor. A 2011 review found the "most convincing" electromagnetic precursors to be ULF magnetic anomalies, such as the Corralitos event (discussed below) recorded before the 1989 Loma Prieta earthquake. However, it is now believed that observation was a system malfunction. Study of the closely monitored 2004 Parkfield earthquake found no evidence of precursory electromagnetic signals of any type; further study showed that earthquakes with magnitudes less than 5 do not produce significant transient signals. The "International Commission on Earthquake Forecasting for