[□]
[□=□]
[!□]
Because current age minus duration of widowhood equals the age at which widowhood began , we cannot infer from our data whether this pattern arises from true duration effects , such as overconsumption of assets , or from effects resulting from age at widowhood , such as greater shocks to lifetime income or stronger income-related selection effects at younger ages . Usually , researchers cannot obtain individual measurements of exposure for all subjects in a study ; consequently , researchers have developed various ways of estimating the exposure of groups of individuals , by re-creating their occupational history and quantifying the related workplace exposures . If the Asian longhorned beetle is left unchecked , damage to hardwood forest trees in public and private forest lands would occur , reducing species diversity and jeopardizing the health and vitality of the ecosystem , and enormous losses that cannot be easily measured to the aesthetics of our woodlands . There is the point of view that the private key has not been used for any non-signature purpose , only the public key , and so the private key cannot be demanded - but if that is to be the case then people could use such use of keys to get around the Act. " I cannot see any difference between Gordon Brown 's policies and his future programme and what there is at the moment .