tax spend spend tax or fiscal synchronization a wavelet analysis in this article we use wavelet methodology to analyse the long term relationship between spending and taxes unlike the standard methodology that utilizes unit roots and cointegration with or with

innovation and social probable knowledge in this paper some elements of keynes s theory of probability are used to under stand the process of diffusion of an innovation based on work done elsewhere it is argued that this process can be viewed as a process of dealing with the collective uncertainty about how to sort out a technological problem expanding the concepts of weight of argument and probable knowledge to deal with this kind of uncertainty we argue that the concepts of social weight of argument and social probable know ledge can be very helpful in understanding the process of diffusion of an innovation

common trends the government s budget constraint and revenue smoothing abstract the requirement that the government s budget be balanced in present value terms is shown to be equivalent to the condition that government expenditures inclusive of interest tax receipts and seignorage be cointegrated the condition is in fact stronger requiring that the deficit inclusive of interest be stationary stationarity of the net of interest deficit is neither necessary nor sufficient for intertemporal budget balance however it does have implications for barro s tax smoothing hypothesis data for the period 1890 1986 are consistent with intertemporal budget balance but not with tax smoothing

knowledge coordination competence creation and integrated networks in globalised firms it is argued in this article that the main problem for the modern globalised firm is not one primarily of the unequal distribution of information but rather of the difficulty of mobilising and integrating fragmented forms of localised knowledge in such a context the role of new means of telecommunication and cooperative working is investigated it is shown that networking favours a transparent mode of governance characterised by inter linked actors and their continuous stimulation thus the con ceptualisation of the globalised firm as a collection of competences offers a frame work for analysing governance mechanisms involving the issue of incentives

expenditures and receipts testing for causality in state and local government finances the results of our tests indicate similarities between the expenditure tax receipt relations of state governments to those previously reported for the federal government in manage and marlow 1986 the results reported here indicate support for the hypothesis that tax receipts cause expenditures at the state level of government for tests utilizing symmetric lag structures ranging from three to five years state expenditures appear to follow state tax receipts for the shortest lag length 2 2 the determination of bidirectional causality does not make us reject the hypothesis that higher spending levels result from higher revenue levels rather the causality appears to be in both directions for the shortest lag length

panel data modelling and the tax spend controversy in the euro zone this article attempts to differentiate between the debatable tax and spend spend and tax fiscal synchronization and institutional separation hypotheses in order to explore empirically the interplay between public expenditures and public revenues in the economic and monetary union emu member states for this purpose panel data models are derived to test the validity of the four hypotheses in emu countries a notable characteristic of this article is that the four hypotheses are tested by dividing emu countries into various subgroups and using disaggregated data for government expenditures and revenues seeking for the robustness of the empirical evidence the panel data methods of generalized two stage least squares gtsls and generalized method of moments gmm are accordingly applied to identify the relationship between public outlays and taxation receipts gtsls and gmm results strongly support the fiscal synchronization hypothesis implying that budget decision making is significantly influenced b

co integration and error correction models the temporal causality between government taxes and spending several interesting papers have recently considered whether government taxes granger cause government spending or vice versa the findings based on standard granger 6 causality tests are not consistent manage and marlow 10 conclude that when evidence of one way causality exists federal taxes granger cause federal spending while anderson wallace and warner 1 conclude that the evidence supports one way causality in the opposite direction ram 11 reexamining the issue concludes that taxes granger cause spending at the federal level but that spending granger causes taxes at the state and local level von furstenberg green and jeong 13 in another related article examine the tax and spend spend and tax causality issue using a more general vector autoregressive var model they introduce in addition to federal taxes and spending two economic variables the gnp gap and the inflation rate decompose federal spending into several categories and remove the effects of automatic stabilizers when appropriate they find little evidence that taxes granger cause spending and limited evidence that spending causes taxes a finding which corresponds most closely to that of anderson wallace and warner 1 our purpose is to reconsider the causality issue with the aid of co integration and errorcorrection modeling our analysis illustrates with a specific example how sources of causality can be neglected in standard granger causality tests moreover addressing the question of temporal causality between government taxes and spending provides insight as to how different policies might or might not help control the growth of government the results of our estimating various co integration and error correction models with quarterly data suggest bi directional causality between government taxes and spending both for the federal and state and local sectors this finding counters the conclusions of previous studies when annual data are used however our

the evolution of the industrial organisation of the production of knowledge this work elaborates the notion of localised technological knowledge based upon the distinction between information competence and knowledge and analyses the emergence of the new knowledge industry the evolution of the organisation of knowledge production is analysed through four stylised modes scientific entrepreneurship institutional variety vertical integration and technological cooperation the new trends towards the growth of knowledge intensive business service industries are detected and underlined they are considered as the outcome of the institutional formation of a market for knowledge based upon a process of increasing appropriability of localised knowledge based on the blending of generic scientific information and competence and growing scope of applicability via computercommunication systems deverticalisation of research activities from the boundaries of corporations the specification of a demand for technological competence and the specialising of independent firms in the production of technological competence and knowledge

bioenergy policy and market development in finland and sweden abstract the use of biomass in finland and sweden has steadily increased over the past 25 years up to approximately 20 of the primary energy supply in 2001 in both countries most biomass originates from forests forest biomass is now an integral part of modern energy systems although primarily in industry and in the heating sector for example biomass accounts for 7 9 and 53 of the fuel mix in district heating in finland and sweden respectively the general energy policy of both countries has supported biomass for energy over the entire period although specific policies have changed with time research development and demonstration has been continuously supported and some subsidy schemes have been applied in particular for district heating systems dhs and combined heat and power heavy taxation of competing fossil fuels seems to have been the most effective policy instrument although this has been directed mainly at the heat and transportation fuel markets electricity taxes are imposed on consumption industry is largely exempt and do not discriminate significantly between the sources of electricity starting in 2003 sweden will have a quota based system a renewable portfolio standard which is expected to increase biomass based electricity production both countries possess vast and not fully exploited biomass resources in the form of forests and have a history of rational and large scale forestry strong actors exist both with regard to forest ownership and the industrial processing of forest products the user side in particular represented by dhs can also be characterised by strong and professional management over time structures have developed that facilitate an increased use of biomass for energy for example the forest industry infrastructure and extensive district heating actors within these structures have had the ability to react to policies resulting in a stable growth in biomass use

lag length selection and tests of granger causality between money and income one of the most widely accepred relationships in macroeconomics is the positive relationship between the rate of growth of the money supply and the rate of growth of income a diversity of opinion arises however with the attempt to identify a causal relationship between these variables while friedman and schwartz 1963 initiated the empirical investigation of money income causality sims 1972 made the most significant contribution to this literature with a practical application of the criterion developed by granger 1969 for identifying a causal relationship since the appearance of sims s approach and an alternative one advanced by sargent 1976 many researchers have applied these techniques to the investigation of the causal relationship between money and income l with two exceptions hsiao 1981 and mcmillin and fackler 1984 these researchers have arbitrarily chosen the lengths of their distributed lags the purpose of this paper is to test for granger causality between money and income this paper differs from previous work in that considerably more attention is focused on the effect of the lag specification on the test results in particular we investigate the extent to which rules of thumb arbitrary lag specifications and

the fuelwood market in greece an empirical approach abstract wood has been since ancient times the basic household heating medium nowadays wood remains the primary energy source in rural areas of developing countries mainly in africa in greece the domestic demand of fuelwood is relied mainly on the fuelwood domestic supply especially during the post war period the domestic supply satisfies adequately the domestic demand eliminating the role of imports the present study surveys the long run relationship between the fuelwood prices of different forest species in order to determine the role of the special market conditions in their price formation in addition the error correction model is estimated in order to survey the direction of the granger causality among the prices of the fuelwood forest species the implementation of the impulse response analysis and the variance decomposition confirmed that coniferous and beech fuelwood producer price may account for the volatility of the oak fuelwood producer price this result may contribute greatly to the conservation of oak forest an important carbon storage forest ecosystem

government spending and taxation what causes what in the past few years as federal deficits have risen to high nominal levels economists have argued about the effect that raising taxes ostensibly to reduce deficits might have on government spending some economists including milton friedman have argued that raising taxes will simply lead to more spending others including james buchanan and richard wagner have said that the high deficits themselves have been responsible for the growth of federal spending and that if that spending had to be financed completely by direct taxes people would demand that the federal government spend less a third group led by robert barro says that increased taxes and borrowing are results of increased government spending in section ii we briefly review various hypotheses about the relationship between federal government spending and revenues section iii describes the testing procedure used to discriminate between these hypotheses the results of four tests are presented in section iv section v contains a summary and major conclusions to foreshadow what follows we find no evidence that higher real federal taxes today lead to either higher or lower federal spending tomorrow on the other hand we find strong evidence that higher spending now will lead to higher taxes later our results support a view of the world in which the political system somehow determines how much to spend and then looks for revenue sources to finance that level of spending including direct taxation borrowing and money creation we also find evidence that real federal revenues are positively affected by real gross national product gnp real federal spending also rises with real gnp but it appears to be independent of the rate of inflation

does land property structure affect local development patterns evidence from a greek tourist area this paper attempts to clarify the institutional context and local framework of landed property relations in the local development patterns of a rural space converted into an urban tourist resort on the island of rhodes greece through the diachronic analysis of cadastral data on land property ownership and non market land property transfers and acquisitions direct and indirect state policies land property structures inherited from the past formal and informal institutions enabled agents to establish enterprises of varying types and size socially dispersed landownership is a structural resource that through agency influences local development patterns and land property is repeatedly implicated in the local production and reproduction system

the added worker effect abstract this paper uses the gross change data and cointegration error correction modeling to test the hypothesis of added worker effect in the u s labor market it is shown that prime age males unemployment u m and flows from unemployment to out of the labor force un m cause an increase in prime age and young females flows from not in the labor force keeping house to employment and decrease their flows into unemployment

a comparison of bioenergy policies and institutional frameworks in the rural areas of emilia romagna and norway abstract this paper explores the relationship between bioenergy rural development and related innovation processes in two case studies emilia romagna in italy and norway for a better understanding of the impacts of different policy regimes on bioenergy innovation regional innovation systems theory is used to explain the results emerging from the case studies and to identify the presence of potential elements for innovation we used policy and relevant literature analysis and a grounded approach based on semi structured interviews of relevant actors involved in the local bioenergy system the main findings show that the case studies present consistent differences in terms of policy instruments and socio political dynamics emilia romagna has major weaknesses and threats that hinder innovation but some positive potential elements for the future norway presents stronger local elements for innovation within local bioenergy systems such as the employment of local resources and knowledge but critical market and policy features that threaten further innovation developments the conclusion draws on the comparative analysis to discuss policy implications of the study

tax and spend or spend and tax an inquiry into the turkish budgetary process for resolving the budget deficit problem some economists have advocated spending cuts while others support either tax increases or tax cuts this paper investigates the interrelationship between the two fiscal variables for turkey using bivariate and multivariate cointegrating models the engle granger and johansen tests consistently support the existence of one nonzero cointegrating vector representing a stable long run relationship between government spending and revenues in turkey furthermore the multivariate error correction model suggests that taxes unidirectionally granger cause negative changes in spending in accordance with the buchananwagner hypothesis thus from the perspective of policy making and the deficit solution debate raising taxes in turkey is perhaps the optimal solution to the current budget deficit predicament contemporary economies perhaps without exception have been plagued with huge and escalating government budget deficits these deficits are expected to have adverse economic consequences including high real interest rates slow capital formation and high unemployment rates moreover to the extent that the deficit is financed through the issuance of government bonds the recurrent large deficits have further worsened the public debt problem which threatens the well being of numerous countries both developed and developing therefore researchers and policymakers have expended enormous efforts attempting to analyze the deficit problem and to suggest ways to resolve it some for example advocate cuts in government spending rather than tax increases as the optimal solution to the deficit dilemma they reason that governments often spend all that they receive in taxes and perhaps much more under this line of reasoning raising taxes would simply induce more spending leaving the deficit unchanged or even higher others however deny this implied tax and spend nexus and argue that it is taxes that adjust gradually to spending under this latter scenario tax increases will not lead to higher spending and thus could be used as an effective deficit cutting measure along with spending cuts still other researchers posit that changes in spending and taxes could occur simultaneously therefore focusing on one component of the government budget while ignoring the interdependence with the other component would have an ambiguous overall effect on the deficit

autoregressive modelling and money income causality detection abstract a step wise procedure based on granger s concept of causality and abaike s final prediction error criterion is suggested as a practical means to identify the order of lags of each variable in a multivariate autoregressive process the model seems useful because it can serve as a reduced form formulation to avoid imposing often spurious or false restrictions of the model it also provides a reasonably powerful test of causality the idea is applied to u s postwar money and income data it is found that between m1 and gnp a bivariate feedback model fits the data best between m2 and gnp a one way causal model from money to income performs better diagnostic checks applied to our model seem to indicate the adequacy of our approach

on the difficulty of eliminating deficits with higher taxes some canadian evidence government budget deficits have increased along with government revenues from direct and indirect taxation both in absolute amounts and as a share of national income in canada as well as in several other countries especially since the 1960s this phenomenon also has coincided particularly since 1980 with skepticism over the notion that government deficit spending stimulates economic growth and employment instead many now expect deficits to produce negative effects on economic activity including high real interest rates reduced real capital formation and production increased unemployment and possible long term inflation 2 these expectations have produced a near concensus on the need to reduce government budget deficits but not on the means of achieving that goal some advocate reductions in government spending as the optimal solution while others call for increases in taxation to raise revenue although either policy in principle may achieve the same result for the deficit they arise from different theories of the determinants of government spending in particular those who advocate expenditure cuts suggest that increased taxation would increase government spending more than it would reduce the deficit arguing that there is a causal direction from increased tax revenues to increased government expenditures although the taxation spending causality hypothesis has assumed increased prominence over the last decade 3 little statistical testing has been done for canada studies by manage and marlow 18 and ram 21 lend support to the argument that expenditures are more responsive to revenues than the reverse on the basis of u s data indeed ram s work contradicts the earlier conclu

government expenditures and revenues evidence from asymmetric modeling 1 introductionexamining the empirical relationship between government revenues and expenditures is a crucial step in understanding the future path of the budget deficit four alternative explanations have been used to describe the relationship between these variables in the budgetary process i the tax and spend hypothesis ii the spend and tax hypothesis iii the fiscal synchronization hypothesis and iv the institutional separation hypothesis the issue of which hypothesis best describes the nature of the budgetary process has yet to be resolved in the literature however existing research has implicitly assumed that the state of the budget and whether or not the budget deficit or surplus is worsening or improving does not matter we argue that government decision makers may take these factors into account when determining expenditures and tax policy as such this article reexamines the tax spend debate by using a more robust econometric technique that allows for asymmetry in the relationship between revenues and expenditures until now the empirical evidence on the tax spend debate has focused almost exclusively on two conventional econometric techniques depending on the cointegrating properties between revenues and expenditures these techniques are based on either variations of the unrestricted vector autoregression uvar or the vector autoregression error correction model ecm 1 if for example the two budgetary variables are not cointegrated then the application of causality2 tests requires the use of stationary variables in the uvar model 3 on the other hand if the two budgetary variables are cointegrated then the application of causality tests requires an ecm specification it is important to note that the ecm specification implicitly assumes that the adjustment process of expenditures and revenues due to disequilibrium between the variables is strictly symmetric indeed if the adjustment is asymmetric then the symmetric adjustment implicitly assumed in the conventional techniques to ascertain causality implies model misspecification this specification error may lead to misguided and perhaps inappropriate fiscal policy decisions accurate estimation of the revenue and expenditure process is especially important as changes in taxes and spending alter incentives for work investment and productive activity cea 2004 thus the anticipated behavioral responses of households and businesses may be better captured by more general models that allow for asymmetry in the tax spend relationship to this end this article examines the existence of cointegration between revenues and expenditures and the corresponding ecm specification by using the recently developed techniques of asymmetric modeling in particular we employ the threshold autoregression tar and momentum threshold autoregression m tar models developed by enders and granger 1998 and enders and siklos 2001 within the context of these models we shed new light on whether budget surpluses versus budget deficits or an improving budget versus a worsening budget have asymmetric effects on the dynamic behavior of expenditures and revenues there is an a priori rationale for modeling asymmetry in the budget and for the response of its components to disequilibrium this rationale can be categorized into four factors first the fiscal policymakers may respond differently to a deviation of the deficit or surplus from its long run trend one would expect for example that the response would be more aggressive if the deficit was greater than its long run trend than if it was less than its trend second it is widely acknowledged that there is a very close connection between the budget and the business cycle through automatic fiscal stabilizers and discretionary fiscal measures to the extent that the business cycle is asymmetric the associated change in the budget may also be asymmetric

testing for the government s intertemporal budget restriction in brazil during 1823 1889 this article tests whether the government s intertemporal budget restriction was fulfilled during the brazilian imperial period 1823 1889 to accomplish this newly developed tests for cointegration with unknown structural breaks are applied it is found that government spending and government revenue are cointegrated if the effect of two unknown structural breaks is taken into account the estimated parameter vector reveals that the one by one relationship that is required for solvency does not prevail for the sub periods before and after the first break however it prevails for the sub period after the second break we interpret these findings as empirical support for the long run government solvency in brazil at the end of the imperial period

government revenue and government expenditure nexus evidence from developing countries the relationship between government revenue and government expenditure has attracted a lot of interest given its policy relevance particularly with respect to budget deficits the goal of this paper is to investigate evidence for causality between government revenue and government expenditure within a multivariate framework by modelling them together with gross domestic product for 12 developing countries our application of the toda and yamamoto 1995 test for granger causality reveals support for the tax and spend hypothesis for mauritius el salvador haiti chile and venezuela for haiti there is evidence for the spend and tax hypothesis while for peru south africa guatemala uruguay and ecuador there is evidence of neutrality

do revenues or expenditures respond to budgetary disequilibria the post world war ii increase in the size of the federal government has led to a number of theoretical and empirical investigations of the sources of this growth in particular economists have questioned whether increases in the size of the federal budget tend to be initiated by changes in expenditures followed by revenue adjustments by the reverse sequence or both friedman for example argues that governments adjust expenditures to the level of revenues so that control of taxation is essential to limit growth in government 13 alternatively the spend and tax model posits that revenues will be adjusted to finance any politically chosen level of expenditures a third perspective reflecting the institutional separation of allocation and taxation functions of the federal government hypothesizes the independent determination of revenues and expenditures the goal of this investigation is to test these three alternative theories of the budgetary process for the united states

small streams diverse sources who invests in renewable energy in finland during the financial downturn this article addresses the investment gap in renewable energy sources identified by several authors examining the case of a country finland which introduced policy measures to diversify its renewable energy portfolio we analyse the development of investments in renewable heat and power in response to new policy measures and contextual factors during the downturn period 2009 2013 we investigate investor heterogeneity i e the diversity of logics employed by different types of res investors in spite of a severe financial recession we find an emergence of new sources of investment among these new investor types we find diversity in investment drivers and available options these include investors mobilized by the feed in tariff to seek profitable targets and investors such as real estate owners investing in heat pumps for their own use and benefiting from low interest rates we find that the diversification of investors supports the diversification in res sources and brings in new investors undeterred by the financial downturn our findings imply that policy makers should recognize that the responses to distinct incentives and pressures vary by investor types this also means that a mix of policies is required to maximize the contribution of different sectors to filling the renewable energy investment gap

re regulating district heating in sweden abstract the electricity market reform in sweden has had great but little discussed consequences for the district heating industry formerly regulated municipal district heating companies are now obliged to operate in a commercial manner and pricing previously regulated by the local authority act is now free the swedish competition authority has on several occasions mentioned to the government that a price regulation ought to be reinstated since district heating is a natural monopoly and in many cases in a dominant market position on local heating markets the competition authority also believes that cross subsidies occur in multi service utilities i e between monopolistic district heating and competitive electricity production and sales municipal district heating is often organised together with electricity sales and production in a municipally owned limited company many municipalities have recently sold their energy utilities to private or state owned commercial actors thus creating private monopolies exempt from price regulations in 1999 the national energy administration stem was given the task to monitor the district heating market and to suggest means to come to terms with these issues stem does not favour a price regulation as the first measure stem also has an operative goal of increasing the use of district heating as a means of reducing electricity dependence in the heating of premises here an interesting conflict of interest exists between the two government authorities we argue that the differences in opinion go beyond the actual tasks given to the authorities but rather depend on perspectives economics and consumer perspective versus an engineering environmental and production perspective we would also like to encourage a broad discussion about the state of district heating and its regulatory condition and that neither economical models nor energy models are taken for granted

environmental taxes on fuels and electricity some experiences from the nordic countries in economic theory environment based energy taxation provides a direct financial incentive for environmentally sound economic behaviour in the energy field in practice only a few countries have implemented such taxes unilaterally in the 1990s to be effective environment based energy taxes seem to need international implementation the eu commission has made three proposals in 1992 1995 and 1997 but so far none of them has proceeded in the negotiations in this article we focus on implemented environmental taxes on fuels and electricity in the nordic countries firstly the idea of environment based taxes as a part of sustainable energy policy is presented secondly we review the impacts of this kind of taxes on the environment energy production and consumption income distribution and competitiveness via estimates presented in the literal sources thirdly we review comparative studies of environmental taxes on energy from a methodological perspective and finally we analyse the use of energy tax comparisons in political decision making a recent energy tax reform in finland is used as an example

the intertemporal relation between government revenue and expenditure in the united kingdom 1750 to 2004 we examine the intertemporal relation between government revenue and expenditure in the uk during 1750 to 2004 we pay particular attention to long run trends by applying a battery of unit root and cointegration techniques to the data and we use a modified granger causality test on data spans organized around structural breaks in the series the results suggest that allowing for structural breaks uk real revenue and spending are i 1 series and cointegrated and that granger causality runs from government spending to revenue as such the spend tax hypothesis appears to best characterize the long run intertemporal relation between government revenue and spending in the uk

the causal relation between federal expenditures and receipts federal expenditures have consistently exceeded federal revenues since 1970 in fact the federal government has seen a surplus in only five years since 1950 the symptoms of such fiscal imbalance are of course budget deficits while budget deficits are nothing new in u s history the recent and projected size of the deficit during peacetime nonrecessionary years has been the cause of much concern to academics the news media and politicians this preoccupation with federal deficits has produced a variety of policy proposals to deal with them

mr keynes and the neo schumpeterians contributions to the analysis of the determinants of innovation from a post keynesian perspective abstract the purpose of this paper is to discuss the importance of knowledge both tacit and codified in the formation of the state of long term expectations that drive firms decisions to search for innovation and to investment in r d the paper takes the post keynesian theory as reference associating it with the neo schumpeterian analysis of innovation dynamics first it is argued that knowledge plays a crucial role in building agents confidence emphasizing that radical innovations are more dependent on the accumulation of codified knowledge given the higher degree of uncertainty associated with this type of innovation while incremental innovations are more dependent on tacit knowledge about the current market conditions and technological trajectory second it is argued that the accumulation of knowledge and the constant introduction of innovations foster the creation of a convention to innovate which facilitates the decision to pursue innovations by influencing long term expectations

tax and spend spend and tax or fiscal synchronization new evidence for ten countries cointegration and vector autoregression are used to test the tax and spend spend and tax and fiscal synchronization for ten countries using annual time series data over the period 1951 to 1996 three of them are part of the newly industrialized countries of asia south korea taiwan and thailand and seven are industrialized countries australia canada japan new zealand south africa uk and the usa this paper includes gdp as a control variable into the model like baghestani and mcnown 1994 ross and payne 1998 and koren and stiassny 1998 the johansen 1988 and johansen and juselius 1990 cointegration test results indicate that these three variables are cointegrated with two cointegrating vectors for south korea one vector for australia canada south africa taiwan uk and the usa and no vector for japan new zealand and thailand the results from granger causality tests suggest unidirectional causality running from revenues to spending supporting the tax and spend hypoth

factors affecting wood energy consumption by u s households about 23 of energy derived from woody sources in the u s was consumed by households of which 70 was used by households in rural areas in 2005 we investigated factors affecting household level wood energy consumption in the four continental u s regions using data from the u s residential energy consumption survey to account for a large number of zero observations i e households that do not burn wood left censored tobit models were estimated urban rural location is a key determinant of level of household wood energy consumption wood energy consumption elasticity with respect to non wood energy price changes was 1 55 at the u s level and a much higher 2 30 among rural households while household wood energy consumption was affected primarily by non wood energy price in rural areas it was influenced mainly by household size and level of income in urban areas elasticity of wood energy consumption with respect to income can be positive or negative depending on household urban rural location region and income level newer houses were found to use less wood energy than older ones and greater urbanization was found to have negative effect on wood energy use our findings suggest that policies reducing relative wood energy cost or increasing non wood energy prices in the residential sector will result in greater wood energy consumption in the u s the effect of policies may vary by region and are likely to be more effective in u s rural areas and in the u s midwest in particular