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. Economic evaluation of mosquito control and narrow spectrum mosquitocide development in California . show the effect of a unit change in any given exogenous variable on the expected value of a contemporaneous endogenous variable after all the simultaneous effects of the system have been worked through. In the abatement model, a change in the stock of sumps, ponds, etc. (Kjy), or the sum of locations treated with pesticides (K20) will occur with changes in the corresponding endogenous variables (K7) and (K5), respec- tively. The impact multipliers for the exogenous variable K^y and K20 on the
. Economic evaluation of mosquito control and narrow spectrum mosquitocide development in California . show the effect of a unit change in any given exogenous variable on the expected value of a contemporaneous endogenous variable after all the simultaneous effects of the system have been worked through. In the abatement model, a change in the stock of sumps, ponds, etc. (Kjy), or the sum of locations treated with pesticides (K20) will occur with changes in the corresponding endogenous variables (K7) and (K5), respec- tively. The impact multipliers for the exogenous variable K^y and K20 on the endogenous light-trap index variables K^, K]^o» ^12 > thus show the immediate indirect effect through the effectiveness equations of source reduction and pesticide use control methods. Of greater impact are the longer-term indirect effects of control methods. The recursive form of equation (2) clearly recognizes that pesticide resistance is genetically transmitted to future generations; and likewise a source reducing pond or sump will show positive results for a number of years. This intertemporal effect has been noted in the context of a user cost earlier in the report. The effect of a unit change in an exogenous variable sustained for a period of time on the expected value of an endogenous variable is 14/ For a review of impact and t period dynamic multipliers see Goldberger [1964], pp. 374-375 or Dhrymes [1970], pp. 521-525.
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Keywords: ., bookcentury1900, bookcollectionamericana, booksubjectmosquitoes