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Conservation . Elongated Elephant. Bulte, Van Kooten. CITES Bans TRADE in endangered species Reduces Demand Should be good for elephants, etc (Same argument for Viagra saving Rhinos). Poaching. Poaching model is the fishing model, but adds enforcement. P price E effort (poaching
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Bulte, Van Kooten • CITES • Bans TRADE in endangered species • Reduces Demand • Should be good for elephants, etc • (Same argument for Viagra saving Rhinos)
Poaching • Poaching model is the fishing model, but adds enforcement. • P price • E effort (poaching • B enforcement effort • X stock • F fine (punishment)
kExp is revenue as in fishing • C(B) E is cost of poaching and increases in B, enforcement. Costs of evading getting caught. • T E (zkEx +p) expected value of punishment • TE is likelihood of getting cauth • Last element is the fine where z is a parameter • Notice that this term has two E’s which drives everything
Zero Profits for Long Run • 0 = kExP – C(B) E – TE (zkEx +p) • Zero long run profits • Gives E(P, B, …) • Point is that poaching increases in price and decreases in enforcement. • h = kEx is harvest
Look at the Table • CITES goes Along with • DECREASED enforcement • Reminiscent of Kip Viscusi’s idea of a taste for danger. (Gov makes you wear seatbelts, so you drive faster to get in your danger quota.)
Social Planner Problem • 1 Elephant = 4.7 cows in terms of forage • D(x) is foregone forage • W(B) costs of enforcement • R(x) are the existence values and tourism values • zTh is the value of the gov’t seized ivory • Q is total sold ivory including legal harvest and illegal
maximand • At each time • P(Q) Q +R +zTh –cE –D(x) – w(B) • S.t. dx/dt = G(x) – h – y • Assumes CITES, only a local market
With trade • Here P(Q) is world price • Big question is how much local price is below world price, even after otpimization. • Now problem is linear in y, so get most rapid approach
Model is really… • Most efficient way to harvest animals • Poach or cull • Right number of animals • Since CITES doesn’t prohibit gov’t from culling, it just reduces price.
Bulte and KC • Program this up with Zambia values and they get
So • Elephants are on their way DOWN, Cites or no. • CITES doesn’t do that much. • Underlying reason—strong local market, possibly driven by smuggling.
ESA • Endangered Species Act • Listing • Take • Includes annoying • Applies to private land too • Habitat Conservation Plans • Can include a whole county • E.g. each acre of toad habitat you take you have to buy 5 acres and preserve them elsewhere
The ESA was not thought to be radical when it was passed. Barely any debate. • Court action and interaction with NEPA made it a very powerful tool • The HCP element allowed negotiation and it is now just another part of doing business
ESA • See Gardner Shogren • Most listed animals aren’t going to recover • There is far too little money allocated to recovery plans to make progress • Total value of the animals would need to be improbably high for it to be right for Congress to allocate that much money
Who gets listed? • Amy Ando sets up model where listing depends on things like “fur” • And also depends on pressure group activity • She records whether there was comment for or against a listing. That is her measure of pressure.
Payoff to a group depends on the other groups actions. The more pressure the other group applies, the more beneficial it is for the group to apply pressure. • Defines a game where the Nash non coop soln is of the form P(i) = a + bP(j) for the two groups i and j.
comes down to lobby is a function of furriness and other groups action. • finds that other groups action doesn’t matter • but furriness does.
Pests • Pests are un elephants. • They are small • We want them dead but • We don’t want to kill ourselves and everything else killing them
Pest Control • Cotton, veggies are a big users of pest control • Obvious problem is that pest control materials can • Run off and kill good things • Bio accumulate and kill bigger animals • Like ddt and birds • Some materials cause cancer, reproductive harm and so on. • FERPA regulates these things • Sunding, Zilberman, Siebert worked on costs of regulation in CA
Cotton • Livingston, Fackler • Two pests, boll wevil and budworm • Two controls: BT cotton and pyrethroids • Also a refugia • Place where we don’t use control/controls • Problem: Bugs become immune to controls.
Biology • Assume single gene for resistance • x,X alleles for resistance/suspectibility for BT • y,Y for pyrethroids • x(t,i) proportion of allele in growing season t and generation i. Multiple generations per season • g is probability of xy etc
Since each plant has two (is diploid) alleles there are 9 genotype frequencies. • See paper for a list and their probabilities. • Each plant is two choices from the four possible xy combos with their frequencies g. • This makes a 9 vector of frequencies for a generation
Pests spend some time in refugia and some in cotton. • first generation, 95% of pests in non selective environment • then 98% of budworms in cotton • and so on.
Different survival rates in refugia vs in sprayed/Bt cotton. • So at end of generation, different percent of alleles in population. • Bigger refugia, higher percent of suspectibles maintained.
Problem • Max money • subject to allele dynamics • choose refugia size, how much to spray • findings: use less sprayed refugia and less refugia all together.