We obtain semiparametric efficiency bounds for estimation of a location parameter in a time series model where the innovations are stationary and ergodic conditionally symmetric marginale differences but otherwise prossess general depence and distributions of unknown from. We then describe an...

As pointed out by Hall (1988), intertemporal substitution by consumers is a central element of many modern macroeconomic and international models. We argue that Hall's estimator or the IES is downward biased because the intra-temporal substitution between nondurable consumption goods and durable...