Biodiversity Conservation Under an Imperfect Seed System: the Role of Community Seed Banking Scheme

Transcription

1 Bodversty Conservaton Under an Imperfect Seed System: the Role of Communty Seed Bankng Scheme MINTEWAB BEZABIH Department of Economcs Göteborg Unversty SWEDEN Abstract:-The study s an emprcal nvestgaton of agrobodversty conservaton decsons of small farmers n the central hghlands of Ethopa. The prmary objectve s to measure the effectveness of Communty Seed Bankng (CSB) n enhancng dversty whle provdng productvty ncentves. We employed Amemya s GLS estmator to nvestgate smultanety between partcpaton and the level of dversty. Our results ndcate a sgnfcant mpact of partcpaton n CSB on farm-level agrobodversty. However, farmer knowledge and experence assocated wth bodversty conservaton were not found to have the expected renforcng mpact on the degree of bodversty. CSB partcpaton also led to a moderate productvty ncrease consstent wth the need for such ncentves to enhance dversty at a farm level. Our assessment of the performance of the GLS estmator yelded sgnfcant dscrepancy between the GLS and bootstrap estmates. Ths led to the concluson that bootstrappng asymptotc estmatons mght be requred for approprate nference even when sample szes are reasonably large. Key-Words:- Agrobodversty, Communty Seed Bankng, Smultaneous equatons, Bootstrappng 1. Introducton The focus of sustanable agrcultural development has for a long tme been the management and utlzaton of abotc resources. The subsequent neglect of bologcal resources n agrculture and ther approprate utlzaton has led to tremendous agrobodversty losses wth notceable consequences. 1 The loss n agrobodversty ntally trggered the establshment of ex-stu germ plasm banks where genetc materals are collected from localtes and stored n the banks. Ths approach was crtczed by evolutonary bologsts and many others snce the genetc materals conserved theren are frozen aganst the course of evoluton [17]. However, genetc materals conserved n- stu 2 evolve aganst natural and man-made stresses whch makes them more valuable compared to ex- stu conserved materals. 1 The extent of agrobodversty loss and ts mplcatons are revewed n Thrupp (2000) and Heal et al. (2004). 2 In-stu conservaton s the conservaton of ecosystems and natural habtats and the mantenance and recovery of vable populaton and speces n ther natural surroundng and n the case of domestcated or cultvated speces n ther surroundngs where they have developed ther dstnctve propertes (Artcle2, Conventon on Bodversty, 1994). Despte ts potental merts, ensurng an approprate level of n-stu conservaton consttutes a major challenge to polcy makers and development practtoners. Ths s manly due to concerns that favorng dversfcaton at a farm level mght compromse the productvty benefts of specalzng n a few crops. Enhancng farm level conservaton wthout foregong productvty, thus, calls for nterventons that provde the approprate (extra) ncentves. Communty Seed Bankng (CSB) s one such scheme amed at provdng a secure local seed system (as an addtonal productvty ncentve) and enhancng farm level agrobodversty [13; 4]. The scheme nvolves multplcaton, storage and dstrbuton of varetes that are ether currently planted by some farmers but that others do not have access to; or varetes that are not currently planted by farmers n the localty but are ether avalable n other localtes or n central Gene Banks. The effcacy of CSB s based on two premses. One s that the CSB seed system expands the avalablty of local varetes to ndvdual farmers, and therefore ncreases dversty. The other premse s that gven mperfecton n the already exstng seed system, provson of seed varetes would ease constrants

2 to seed access, mprove overall resource allocaton and ncrease productvty. 3 In lne wth ths, the study ams at assessng the effectveness of partcpaton n CSB n enhancng agrobodversty and ncreasng farm-level productvty. In an attempt to properly assess the mpact of CSB partcpaton on farm level dversty, we consder the knowledge and experence that farm households have n managng local varetes and n conservaton as potental determnants of partcpaton. Snce experence s drectly assocated wth the level of conservaton, assessng the effectveness of such schemes wthout takng nto account the mpact of prevous knowledge and experence would be naccurate due to the problem of endogenety bas. In order to assess potental endogenety, we estmate a smultaneous equaton wth partcpaton and current farm level bodversty (representng experence) as endogenous varables. Due to the mxed nature of the smultaneous equatons, we employ Amemya s GLS estmator, whch s beleved to be effcent n handlng such equatons [25]. To further assess ts relablty, we use the method poneered by ( n whch the estmates from the asymptotc estmator are evaluated aganst bootstrap results. The rest of the paper s organzed as follows. In Secton 2, we present the hypotheses we attempt to test followed by a descrpton of the settng and samplng procedure n secton 3. Secton 4 presents the econometrc model and estmaton technques. The results and dscusson are presented n Secton 5. Secton 6 concludes. 2. Conceptual framework and hypotheses Bodversty loss s assocated wth large farms and massve adopton of mproved varetes, whch are vulnerable to envronmental stresses. On the other hand, bodversty n small farms, whose crop portfolo s domnated by local varetes, s perceved to be ntact. The problem of bodversty loss n such small farms has, as a result, been dsregarded. Ths s partcularly attrbuted to 3 It should be noted that for the ncrease n productvty to be realsed, the varetes need not be nherently more productve than the other avalable varetes; the productvty ncrease comes about because of mprovement n access to seeds and mproved allocaton of resources. observatons that the level of dversty mantaned by farmers ncreases wth market mperfectons and rsk averson: rsk-averse households and households wth low market ntegraton tend to be more dverse [20]. [19] also argue that the survval frst motve could gve addtonal motves to ncrease dversty beyond the level that s trggered by market mperfectons and transacton costs. [8], however, show that from the socety s pont of vew, bodversty wll always be under-nvested at the farm level. Thus, the observaton that small farms mght be more dverse than standard proft optmsaton would predct does not guarantee a level of dversty (at a farm level) that would match the socally optmal level as long as dversty brngs about external benefts to socety. Ensurng a socally optmal level of dversty calls for nterventons that are prmarly effectve n enhancng dversty. Moreover, gven the gap between the ndvdually optmal level of bodversty and that of the socally optmal level, the nterventons should confer addtonal benefts to ndvdual farmers for them to be adopted. CSB s one such nterventon amng at ncreasng bodversty at the ndvdual farm level through provdng local seeds that are not locally avalable or not well dstrbuted across farmers. Thus, we set out to assess the effectveness of CSB n enhancng dversty and productvty. Whle adopton of mproved varetes generally leads to a reducton of dversty [3], there are reasons to beleve that landrace farmng s assocated wth dversty, holdng other thngs constant. Wthn-farm heterogenety wth respect to physcal farm characterstcs s one reason. [14] found that households managng farms wth dverse characterstcs tend to grow more landrace varetes. Transacton costs assocated wth accessng varetes wth partcular qualtes form another reason. [18]noted that Malawan maze farmers tend to grow local varetes for qualty reasons (snce the local maze varetes have superor consumpton qualtes) and especally because t s not certan that the partcular local varetes wll be avalable n the market. Ths s n lne wth [14] observaton that qualty ssues become relatvely unmportant for households that have gven up tradtonal varetes whle hgh transacton costs of obtanng desred qualtes n a partcular varety contrbute to the contnued cultvaton of landrace varetes. Followng ths, we expect adopton of CSB varetes, whch are local, to lead to ncreased dversty. We also expect farm

3 level dversty to vary wth soco-economc and physcal farm characterstcs of the household. Provson of CSB seeds s also expected to ncrease productvty gven the mperfectons n the already exstng seed system. In the case we are studyng, the seed system s comprsed of two sources. The prmary source of seeds s what farmers save from prevous harvests, usually local varetes. Another component of the seed system s the modern component, assocated wth the provson of mproved varetes. Tradtonal seed sources are characterzed by costly storage [13] and also depend on one s ablty to save from prevous harvest. The modern component of the seed system s also characterzed by postve transacton costs to access, ndcated by factors lke costly supplementary nputs, costly expermentaton, seasonal lqudty and famly labour constrants [15]. Postve transacton costs n the already exstng seed system (at least for some) consttute an mperfect seed system, whch leaves room for mprovement n terms of the provson of a relatvely easly accessble source. In lne wth ths we hypothesze CSB to be a seed source whch mproves the already exstng seed system thereby enhancng productvty. Socoeconomc, physcal farm and agroecologcal characterstcs as well as other seed sources are also expected to affect productvty. Prevous studes analyzng partcpaton n agrenvronmental schemes looked nto farmer (e.g.[23]) and scheme factors (e.g. [22]) as mportant determnants of the decson to partcpate and of the degree of partcpaton. In addton, other aspects not captured by farmer and scheme factors, at least not drectly, are also ndcated to be mportant n explanng partcpaton n such programmes. [24] found that percepton of envronmental rsks s an mportant addtonal reason to partcpate n agrenvronmental schemes. In hs analyss of the determnants of partcpaton n the Unsprayed Crop Edges Program n the Netherlands, [21] found that perceptons regardng the envronment sgnfcantly dffer between partcpants and nonpartcpants. In the case of an nterventon lke CSB, partcpaton wll also be a functon of the household s access to other seed sources (and the mpact of other seed sources on partcpaton depends on whether the CSB and other seeds are substtutes or complements). In addton, snce farmer and other behavoural factors would condton prevous knowledge and experence n managng bodversty; we expect farmer knowledge and experence to be mportant determnants of partcpaton n CSB. On the other hand, snce knowledge and experence n managng bodversty are drectly related wth the level of dversty, partcpaton n the CSB and the level of bodversty are endogenous n the respectve equatons. The hypotheszed relatonshps above mply smultanety 4, and assessment of the mpact of Communty Seed Bankng on agrobodversty requres a smultaneous estmaton of an equaton system wth partcpaton and bodversty measures as endogenous varables. Sngle equaton estmaton of such relatonshps causes bas and nconsstency, but approprate nstrumental varable estmators are generally asymptotcally vald. Whle asymptotc estmators 5 are wdely applcable, they generally suffer from the problem of accuracy. As [11] argues, standard errors computed from asymptotcally vald covarance matrces could serously understate true estmator varablty n fnte samples possbly leadng to type I errors n nference. In lne wth ths, a number of studes have appled bootstrappng 6 to mprove the performance of asymptotc estmators. However, the use of bootstrappng has been far from consstent and has largely been based towards small samples. Indeed, prevous studes (appled to small samples) assessng the performance of asymptotc estmators 4 It should be noted that there are no reasons to beleve a pror that productvty drectly affects partcpaton n CSB or dversty. Thus, the productvty equaton whch assesses the productvty mpact of CSB partcpaton s not part of the smultanety. 5 Asymptotc estmators are estmators wth known propertes that apply to large samples and whose fnte sample behavour s approxmated by what s known about ther large sample propertes (Greene, 2000). 6 The bootstrap method s a resamplng method whereby nformaton n the sample data s recycled for estmatng varous propertes of statstcs through drawng random samples from the orgnal sample (Jeong and Maddala, 1993). 6 Sample szes used n prevous studes, whch assessed the performance of asymptotc estmators usng bootstrappng, ranged between 30(Freedman and Peters, 1984) and 128(Des and Hll, 1998).

4 vs-à-vs the bootstrap have confrmed that bootstrap mproves the accuracy of asymptotc estmates (e.g. [6]; [5]). Wth relatvely larger sample szes, however, bootstrappng s less commonly appled to mprove the performance of asymptotc estmators. Thus, to assess the performance of bootstrappng vs-à-vs asymptotc estmators n such a context we employ a sample, whch s reasonably large compared to prevously tested samples. Table 1: Descrptve statstcs of the varables used n the regressons Varables Descrpton Mean SD SOCIOECONOMIC TRAINING WEALTH OXEN AGE FEMALE RADIO FORMAL EDUCATION RELIGIOUS EDUCATION SCHEME LOCATION OF CSB PHYSICAL FARM FARM SIZE MEDIUM SLOPE STEEP SLOPE MODERATELY FERTILE INFERTILE AGROECOLOGICAL GORO ADDADI GOLE BUAE TENGEGO KERSA MENJIKSO KOREMTA SEED SYSTEM IMPROVED SEED FERTILIZER SEED SOURCE OWN SEED CSB SEED BORROWED SEED EXCHANGED SEED EXTENSION SEED MARKET SEED VARIABLES Head wth any tranng (1=yes;0=otherwse) Lvestock holdngs (n tropcal lvestock unt) Number of oxen Age of the household head Sex of household head (1=female;0=male) Rado ownershp (1=yes;0=otherwse) Head s formal educaton (1=yes;0=otherwse) Head s relgous educaton (1=yes;0=otherwse) VARIABLE Locaton of the bank (measured n terms of dstance from homestead to the bank (mnutes) VARIBLES Farm sze (ha) Proporton of flat land n the total farm area Proporton of hlly land n the total farm area Proporton of gorgy land n the total farm area Proporton of land wth good fertlty Proporton of land wth moderate fertlty Proporton of nfertle land VARIABLES Kebele dummy (1=Goro) Kebele dummy (1=Addad Gole) Kebele dummy (1=Buae Tengego) Kebele dummy (1=Kersa ) Kebele dummy (1=Menjkso) Kebele dummy (1=Koremta) VARIABLES Amount of mproved seeds borrowed n 2003 Amount of modern fertlzer borrowed n 2003 (kg) Number of sources a household has secured seeds from (all tradtonal and modern) Proporton seeds from own storage n the total farm Proporton seeds from CSB n the total farm Proporton seeds borrowed from fellow farmers Proporton seeds exchanged wth fellow farmers Proporton seeds from the extenson system Proporton seeds from the market DEPENDENT PARTICIPATION SHANON YIELDV VARIABLES Partcpaton n CSB (1=yes;0=otherwse) Rchness measured n terms of Shannon s ndex Total (wheat) yeld per ha (Br/ha)

5 3 Data, Econometrc framework and estmaton procedure wherey s total yeld and dfferent seed sources. S stands for the The study was conducted n an area wthn the broad agroecologcal zonaton of Ethopa known as the Central Hghlands. The study ste s named Chefedonsa, a woreda 7 wth 30 kebeles, located n the Eastern Oromya Zone of the Oromya Natonal Regonal State. The specfc study ste s a center of orgn and dversty for many wheat and pulse varetes. Due to ths, one of the eleven communty seed banks across the country s located n the woreda. Table 1 gves the lst of dependent and ndependent varables employed n the analyss. Our analyss of the mpact of CSB partcpaton on the level of dversty mantaned by households s based on a smultaneous estmaton of partcpaton and dversty equatons. For the th ndvdual, the partcpaton equaton s thus gven by: P P P 1 f β X + γ D + u > 0, = 0 otherwse (1) where P s an ndcator varable equal to 1 f the respondent partcpates n the CSB, X s a vector of soco-economcs and physcal farm characterstcs, D s the level of crop dversty and u s an error term. The level of dversty mantaned by the household s, n turn, gven by: D D D = β X + γ P + η, (2) where η s an error term. We assume that the errors n the two equatons are ndependently, dentcally and normally dstrbuted error terms wth zero means. The mpact of dfferent seed sources on value of total yeld per ha s explored usng the followng relatonshp : Y Y = β X + λp + ψs > 0, (3) 7 Woreda corresponds to a dstrct whle kebele corresponds to a vllage. Our other measure of productvty, value of wheat yeld per ha unt of plot, s expressed as n equaton (4) wherew s the value of wheat yeld and S stands for the dfferent seed sources. * * Y W f W = β X + λp + ψs > 0, (4) W = * 0 f W 0 Equaton (3) s estmated wth standard OLS and equaton (4) s estmated wth a Tobt model. We employ Amemya s GLS estmator [1], whch, although computatonally nvolvng, s shown by Lee (1981) to be the most effcent of the class of mxed smultaneous equaton estmators [25]. 8 We follow the procedure used n [5] to evaluate the performance of the GLS estmator. The procedure nvolves bootstrappng the orgnal samples to obtan emprcal dstrbuton of the t-values from whch crtcal values are computed. We also use the bootstrapped samples to compute the bootstrap coeffcents and ther correspondng standard errors. To compute the t-crtcal values correspondng to the bootstrap coeffcents, we bootstrap from each bootstrap replcaton and repeat the procedure we used to obtan the crtcal values for the orgnal estmates Results In Table 2, we present the results of the frst structural equaton n whch the left hand sde varable s partcpaton n the CSB. The frst part of the table shows the results from Amemya s GLS estmator and n the second, the results based on the 100 bootstrap samples are reported. Comparson of the bootstrap and GPGLS results s 10 gven n the thrd part of the table. 8 A more commonly used estmator s Heckman s two stage estmator.[9] 9 The software package LIMDEP 8.0 was used to estmate both the asymptotc and bootstrap statstcs. 10 For consstency reasons, we dscuss the dfferent results n the order they appear n the tables. However, our focus of dscusson s the results based on bootstrap crtcal values.

6 Table 2: Comparson of smultaneous equatons wth and wthout bootstrap of the partcpaton functon Varable Tranng Wealth Age Female Rado Formal educaton Relgous educaton Locaton of CSB Improved seed Farm sze Medum slope Steep slope Moderately fertle Infertle Fertlzer Seed source Constant Shanon Amemya s GLS smultaneous equaton estmaton AGLS T-STAT t- crt 11 (α=0.10) 0,144-0,263 a -0,0004-2,860 a 0,747-0,161-0,020-0,165 a -0,019 ab 0,006 a -0,047-0,607-0,662 0,202-6,614 a -0,004 a -0,234 9,581 a 0,267-2,697-0,019-2,376 1,595-0,202-0,041-1,860-2,828 1,766-0,061-0,935-0,911 0,375-2,736-2,706-0,278 2,730 1,819 4,664 2,546 6,661 1,897 2,144 2,010 2,393 2,170 3,119 22,884 4,326 4,360 2,456 7,903 5,088 3,571 5,201 Bootstrappng Amemya s GLS estmator BGLS BT-STAT Btcrt 12 (α =0.10) 0,466 0,784 1,253-0,173-1,143 2,956 0,013 0,533 1,991-3,298-1,024 1,413 0,751 1,431 2,212-0,002-0,002 2,043-0,136-0,267 2,045-0,138-1,154 3,350-0,019 ab -2,192 2,180 0,002 0,342 2,415-0,052-0,069 2,678-0,334-0,414 1,708-1,158-1,236 2,264 0,406 0,685 2,299-4,376-0,987 3,878-0,002-1,153 4,081 0,497 0,367 3,984 6,280 1,116 6,422 Compars on BIAS-T -5,418 ab -5,910 ab -5,473 ab 1,361-0,077-1,664 2,281 ab -2,231 0,446 6,860 ab 0,057-3,388 ab 5,295 ab -3,435 ab -5,047 ab -4,796 ab -5,397 ab 5,867 In the GLS results based on the standard crtcal values, wealth and gender of the household head, CSB partcpaton, whle the other socoeconomc and physcal farm characterstcs are not sgnfcant. study, locaton of the CSB, also has a sgnfcantly negatve mpact on the lkelhood of partcpaton. A comparson of the asymptotc and bootstrappng results shows that all the 11 The crtcal values are obtaned from the emprcal dstrbuton of the bootstrap t-values where each t-value corresponds to a bootstrap replcaton (followng Des and Hll, 1998). We used 100 bootstrap replcatons for the results. 12 The bootstrap t-crtcal values are obtaned from bootstrappng the bootstrapped samples. The bootstrap replcatons n the second bootstrap are 10. a Sgnfcant at the 10% level, usng the standard crtcal value (.e. t=1.64) asymptotc coeffcent estmates except the coeffcents for sex, rado and slope dummes suffered statstcally sgnfcant bases. Table 3: Comparson of smultaneous equatons wth and wthout bootstrap of the dversty functon Varable Wealth Oxen Age Female Rado Formal educaton Relgous educaton Improved seed Farm sze Medum slope Steep slope Moderately fertle Infertle Goro Addad Gole Buae Tengego Kersa Menjkso Fertlzer Constant Partcpaton Amemya s GLS smultaneous equaton estmaton AGLS T-STAT t- crt 13 (α=0.10) 0,029 ab 0,004 0,000 0,283 a -0,072 0,007-0,004 0,016 a -0,001 a -0,103 0,011 0,092 0,108-0,170 a -0,131-0,097-0,154-0,004 0,0004 ab 0,948 a 0,106 ab 0,029 ab 0,004 0,000 0,283 a -0,072 0,007-0,004 0,016 a -0,001 a -0,103 0,011 0,092 0,108-0,170 a -0,131-0,097-0,154-0,004 0,0004 ab 0,948 a 0,106 ab 2,188 2,694 2,715 7,118 2,398 3,162 2,596 4,467 2,381 4,500 21,174 5,220 5,658 2,504 3,091 2,269 2,536 6,308 3,365 6,398 3,384 Bootstrappng Amemya s GLS estmator BGLS BT-STAT Btcrt 14 (α =0.10) 0,026 ab 2,294 2,252 0,009 0,258 1,709 0,000-0,091 2,871 0,326 1,104 2,014-0,078-1,293 1,835-0,007-0,066 2,562 0,000-0,004 2,004 0,020 a 1,829 2,512 0,000-1,259 1,631-0,120-0,986 2,027 0,035 0,463 1,930 0,085 1,017 2,190 0,149 1,422 2,198-0,209-0,619 4,131-0,171-0,509 3,745-0,125-0,379 4,404-0,180-0,530 3,909 0,341 0,337 36,050 0,000 ab 3,136 2,043 0,955 a 2,215 2,205 0,095 ab 4,231 3,843 Compars on BIAS-T 2,474 ab -1,352 2,436 a -1,459 0,977 1,307-0,684-3,338 ab -5,210 ab 1,375-3,157 ab 0,910-3,914 ab 1,151 1,176 0,847 0,758-3,415 a -0,276-0,172 4,711 ab 13 The crtcal values are obtaned from the emprcal dstrbuton of the bootstrap t-values where each t-value corresponds to a bootstrap replcaton (followng Des and Hll, 1998). We used 100 bootstrap replcatons for the results. 14 The bootstrap t-crtcal values are obtaned from bootstrappng the bootstrapped samples. The bootstrap replcatons n the second bootstrap are 10. a Sgnfcant at the 10% level usng the standard crtcal value (.e. t=1.64) b Sgnfcant at the 10% level usng the crtcal value derved from the emprcal dstrbuton of bootstrap t values. a Sgnfcant at the 10% level usng the standard crtcal value (.e. t=1.64) b Sgnfcant at the 10% level usng the crtcal value derved from the emprcal dstrbuton of bootstrap t values.

7 Table 3 presents results from Amemya s and bootstrap smultaneous equaton estmates for the dversty equaton and a comparson between the two estmates. Lke n the partcpaton equaton, many of the GLS coeffcent estmates based on the standard crtcal values turned out to be sgnfcant. However, an evaluaton of the estmates aganst the bootstrap crtcal values shows that soco-economc and physcal farm characterstcs were weak n explanng the level of dversty mantaned by households. The vllage level dummes also had nsgnfcant mpacts on the level of dversty. The mpact of CSB partcpaton on dversty s postve and consstently sgnfcant across estmates. Ths ndcates the effectveness of the CSB scheme n enhancng dversty. As we argued earler, the modern seed system has a negatve mpact on partcpaton. Dscrepancy between the two estmates s stll sgnfcant n the dversty equaton, although, the number of sgnfcant cases s lesser n the dversty than the partcpaton equaton. Table (4) presents the results from the OLS and tobt estmates of the productvty equatons. The soco-economc factors, namely gender, age and wealth of the household head, have turned out to be nsgnfcant n both equatons. The number of oxen, measurng access to tracton power, s also nsgnfcant. As would be expected, the proportons of hllsde and nfertle plots have sgnfcantly negatve mpact on productvty. Also, the mpact of fertlzer applcaton s postve and sgnfcant. Ths shows that farmers are ndvdually ratonal n adoptng dversty ncreasng CSB varetes snce the varetes confer productvty benefts. Table 4: Estmaton results for the determnants of productvty Varable Total yeldv Wheat yeldv Own seed CSB seed Borrowed seed Exchanged seed Extenson seed Female Age Oxen Wealth Farm sze Fertlzer Medum slope Steep slope Moderately fertle Infertle Goro Addad Gole Buae Tengego Kersa Menjkso Constant (2.07)** (0.30) (1.11) (0.08) (0.62) (0.08) (1.63) (0.98) (0.80) (6.45)*** (0.87) (0.81) (2.45)** (0.42) (0.90) (2.12)** (0.68) (0.91) (1.86) (0.66) (3.69)** (0.79) (1.83)* (1.84)* (0.35) (0.00) (1.12) (0.55) (0.73) (0.09) (10.28)*** (2.28)** (0.35) (2.01)** (1.01) (0.26) (2.01)** (0.78) (1.52) (1.92) (0.59) (6.26)**

8 5. Conclusons Bodversty conservaton ntatves n large monocropped farms have been assocated wth monetary compensaton to conservator farmers who choose to engage n the partcular program (see for e.g. [16]). However, n small multcroppng farmng systems wth mperfectons n the seed system, expandng the provson of local seeds sources mght mprove seed access and enhance farm level dversty. In lne wth ths, the study examnes a scheme called Communty Seed Bankng (CSB) whch ams at ncreasng bodversty of ndvdual farms through mprovng the local seed supply system. The partcular objectves of the study have been to assess the effectveness of the CSB n enhancng dversty and n mprovng access to local seeds. We hypotheszed that partcpaton n CSB leads to enhancement of agrobodversty. We also argued that the provson of local varetes n the CSB allevates the problem of seed access and, thus that CSB partcpaton would mprove productvty. In addton, we proposed that the exstng level of bodversty would have a postvely enforcng mpact on partcpaton n CSB. The relatonshps we proposed mpled endogenety of dversty and CSB partcpaton measures. To assess the possble smultanety, we employed the Generalzed Probt GLS estmator, whch was developed by Amemya (1978) to handle smultaneous equatons wth mxed endogenous varables. The performance of the GLS estmator s also examned usng the bootstrappng technque. Our results confrm a sgnfcant mpact of partcpaton n CSB on farm level bodversty. Furthermore, CSB partcpaton was shown to sgnfcantly ncrease the productvty of partcpant farmers. The mplcaton s that agrobodversty conservaton could be effected through a provson of desrable local varetes. On the other hand, the level of dversty dd not have a sgnfcant mpact on partcpaton mplyng that partcpaton s not necessarly condtoned by prevous knowledge and experence wth respect to mantanng dversty. The number of seed sources farmers access seeds from dd not sgnfcantly explan partcpaton. However, access to mproved varetes, whch comprse the modern seed system, were shown to reduce the lkelhood of partcpaton n the CSB. Ths mples that gven the current workng of the seed system, CSB works as an effectve conservaton nstrument for seed-poor farmers who have less access to the commercal seed system. On the other hand, wth mprovement n the workng of the commercal seed system, overall partcpaton n the CSB would fall. Ths further leads to a reducton n the effectveness of CSB as a mechansm enhancng conservaton. Instruments whch explctly reward conservator farmers should be n place for sustanable agrobodversty conservaton n lght of mproved access to the modern seed system, therefore. Our nvestgaton of the performance of the GLS estmator vs-à-vs the bootstrap yelded the result that our asymptotc results were sgnfcantly dfferent from the bootstrapped results. Ths s n lne wth prevous studes whch analysed asymptotc and bootstrappng estmates although our sample sze s consderably large. The mplcaton s that asymptotc estmators mght not be relable even when sample szes appear to be reasonably large. As a result, suffcently large sample szes or technques lke bootstrappng should be used to get accurate estmatons when asymptotc estmators are employed. References [1] Amemya, T.,The Estmaton of a Smultaneous Equaton Generalzed Probt Model. Econometrca 46(5), [2] Benn, S., Gebremedhn, B., Smale, M., Pender, J., and Ehu, S. Determnants of Cereal Dversty n Communtes and on Household Farms of the Northern Ethopan Hghlands. [3] Brush, S. B., Taylor, J. E., and Bellon, M. R. Technology Adopton and Bologcal Dversty n Andean Potato Agrculture. Journal of Development Economcs 39(2), [4] Demsse, A., and Tanto, T. Dynamc Partcpatory Approach to the use of Plant Genetc Resources. Insttute of Bodversty Conservaton and Research Adds Ababa, Ethopa. [5] Des, D. R., and Hll, C. R. An Applcaton of the Bootstrap Method to the Smultaneous Equatons Model of the Demand and Supply of Audt Servces. Contemporary Accountng Research 15(1), [6] Freedman, D. A., and Peters, S. C. Bootstrappng an Econometrc Model: Some Emprcal Results. Journal of Busness and Economc Statstcs 2(2),

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